Wikipedia:Reference desk archive/Computing/2006 August 9

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[edit] Internet connection failure after a BSOD.

I'm running Windows XP and connected to the net by DSL. Some nights, I'll get a blue screen of death (error: Driver IRQL is not less or equal) and reboot. When I try to connect to the internet, I get a variety of errors; Username and/or password invalid on this domain and The remote computer did not respond in a timely manner. Often I'll get one of these errors, then the other, then the first again, then the other -- ad nauseum, for two to five hours. I'm assuming this is something on my end, as my ISP-mates at Whirlpool -- an Australian ISP discussion forum -- didn't experience this. Is this something I can fix? I only have unlimited downloads between 10PM and 7AM, so the internet being down between these hours is a huge pain.

Well, I'd try resetting your modem and router. That may or may not fix something. Also, you can try using system restore to set your machine back to a working state. (btw, usually WinXP is stable enough not to go to BSOD mode. You probably f-ed your system somehow).--Frenchman113 on wheels! 13:41, 9 August 2006 (UTC)
I don't use a router, and my modem is a very basic USB modem with no switches, buttons or browser-accessible settings. Is it possile to reset it?
Can u find out what drivers caused the error?It is given at the bottom of the blue screen. Mostly they are video driver errors or software incompatabilities, but if u experience this during torrent downloads, u can suspect the client. uTorrent client is particularly known to have some issues with some hardware setups. Some client which worked very well once may suddenly start developing problems,too. The problems can be any of these-(it can be a good starting point)
1.change in tcpip parameters due to system restoring/similar actions
2.network interface driver corruption/out of date
  -uninstall and reinstall latest nic drivers
3.ide driver conflicts(running in reduced dma modes)
  -check 80 conductor cables,
  -master/slave settings,
  -uninstall and reinstall ide controllers and set to "dma if available"
4.pci bus driver corruption
  -reinstall
5.graphics driver problems
  -reinstall latest drivers
6.max number of connections- problem
  -there is a MaxNumConnections dword in registry(not that helpful)(google search) 
7.download/upload speed limit-issues
  -limits too low can cause probs
8.dhcp server issues(if running software proxies)
  -set static IP for ur LAN connection

[edit] installing linux in my 915 gav intel mother board

hi i want to know the correct version of linux that i can install in my original intel 915gav mother board..

please give your valid suggestions....

There's no wrong version of Linux... --the linux chica.
Just find the Linux distro you want. Judging by your question, I don't think you're ready for Linux quite yet. That's honest advice. You should read up a bit more about Linux, its history, how it works, and the various distrobutions. If you insist, Ubuntu is the favorite distro at the moment. --mboverload@ 13:11, 9 August 2006 (UTC)
Ubuntu is a great migration OS. As is Xandros OCE. Also, once you are ready for more Linux-y distros, Slackware is great. Very stable. Very reliable. And can be configured to look like W***ows. --the linux chica.

[edit] AMD processor

Hi, i would like to know what is the difference between AMD Sempron 3000 and the AMD Ahtlon64 3000. Is there an advantage by on over the other? thanks, Jon

See our articles Sempron and Athlon64. The question is meaningless without more details.-gadfium 09:28, 9 August 2006 (UTC)


Sempron 3000 have less cache and a lower clock than its athlon brother also depending on the model the 3000 sempron might be a 32 bit CPU where the atlon is a 64 bit CPU and the question is not meaningless with out more details you just cant give fully detals about it

[edit] LCD monitors

I'm looking to buy a new LCD monitor, and I would like to know what is the respnose time that I need to see clearly movies, games(even though I don't play that much). Is 8ms enough, or should I look for one with 4ms?

It depends on how they measure the response time. 8ms is fine, but I'm a gaming asshole so I'd go for 4ms, since ~13ms is your human response time to something on the screen. --mboverload@ 13:12, 9 August 2006 (UTC)

As for movies, I don't think the speed matters at all. Even if you had one with a 100ms response time, you would still see the movie the same as with a 1ms response time, just 99ms later. StuRat 16:40, 9 August 2006 (UTC)

I think you are slightly missing the point of the term 'response time' when it comes to LCDs. The time is measured as the period that a subpixel is in flux between its starting intensity and the target intensity, meaning that it will be a 'blur' for that long since its not quite where it was and not quite where it should be. This means that, for example in 60fps video, a new frame needs to be drawn every 16.6ms (1000ms/60fps) and if the monitor has for example 8ms response time it will get the pixels changed in 8ms, leaving 8.6ms of solid pixel time before the drawing starts again. A time of over 16ms is obviously unusable since a fast moving scene (in a video game or other fast multimedia) will be a constant blur, and times that fall below that will incrementally be better on your eyes since you will see a more steady image. Back to the subquestion: Movies. Movies are shot at 24FPS, and are sometimes pulled down to 30fps or 60fps depending on the electronic media they are transferred to. If you are watching the pure cinematic version at 24fps you will need to draw a frame every 41ms, and a pulled down version at 30fps will still only need one frame every 33ms, leaving plenty of time for a stable image. I hope this has been as enlightening. --66.195.232.121 14:50, 11 August 2006 (UTC)
Anything under 12ms is fine. Anything under 8ms is probably overkill. In fact, I'm an avid gamer and my LCD monitor is a relatively high 16ms: I really haven't noticed it at all. Sum0 20:05, 12 August 2006 (UTC)

[edit] Windows XP Taskbar Problems

I have Windows XP SP2, and my computer was fine yesterday, but now none of the buttons on the taskbar work. The start button doesn't work, none of the quick launch buttons work. And I had it on autohide so now it's hidden and I can't bring it back up again by hovering over the bottom of the screen like I usually do. Please help.--Anakata 10:39, 9 August 2006 (UTC)

Explorer.exe handles the taskbar, AFAIK.
  1. If you can launch the task manager (by first pressing Alt-Ctrl-Del), bring it up
  2. check if explorer.exe is running
    • If it isn't, choose Files → New task → navigate to C:\Windows\explorer.exe (or wherever it is) and run it.
    • If it is running, kill it, and run it anew. --Kjoonlee 11:14, 9 August 2006 (UTC)
Thank you so much! It's working now.--Anakata 14:08, 9 August 2006 (UTC)

[edit] uTorrent failings

Here's a link to my uTorrent screen -- http://img65.imageshack.us/img65/9718/untitledez4.png . As you can see, it's only going at 60-80kb/s even though I have a max of 150kb/s, and several of the downloads have heaps of seeds. Is the problem on my end?

The problem here is that your upload cap is too low. Increasing your upload limit to 80% of your max is recommended (but don't set max connections to 999... that'll ddos your connection). Further, it's not entirely unusualy to get lower than max speeds with BT, especially on torrents with fewer seeds/peers (sheer numbers count too). Judging from your screen, your ports seem to be open, so port forwarding isn't going to help. But, you're just downloading too many torrents at once. for 17kbps up, you should limit to 2 active torrents. Queueing should reduce overall download time. Lastly, if you're downloading during peak traffic hours, your ISP may not have enough bandwidth due to overselling (possibly also downthrottling your bt, but that doesn't seem likely in this situation.)

[edit] Multi-Monitor MPG Player

I have a 2 monitor PC (running XP), with the second monitor connected to a projector for doing presentations. I'm looking for a good program to play MPG files, with these features:

- Ability to play full-screen on the second monitor
- Black screen with no logo or splash screen when stopped or between MPG files

Any recommendations? The best I can do now is Windows Media Player, size the window "really big" - bigger than the screen resolution of the second screen, and drag it over so you can't see the controls. -Mr.Logic 13:29, 9 August 2006 (UTC)

I would recommend VLC Media Player, though I've never used a dual-monitor setup.
What video card are you using? If it is capable of dual monitor output, I'm sure there should be some settings on the video card's Control Panel to manage this, or even the Display Control Panel. --Canley 14:47, 9 August 2006 (UTC)
Thanks, "VLC Media Player" looks like it will do the job. It doesn't have dual-monitor support, but I think I can force it over using "UltraMon".
In this case, the specific card doesn't matter. The vast majority of apps that display full-screen force to the primary monitor, and aren't dual-monitor friendly.
If anyone else has suggestings, I'd welcome them as well...
-Mr.Logic 16:42, 9 August 2006 (UTC)
Update: the process ain't friendly, but I foudn exactly the settings I need in VLC.
http://forum.videolan.org/viewtopic.php?t=14279&highlight=dual+monitor
-Mr.Logic 16:57, 9 August 2006 (UTC)

[edit] Customising Windows Explorer in NT4.0

I'm running NT4.0 on my home computer (don't ask, suffice to say I'm very happy with it). Is there a way of customising WE so that it doesn't open to an expanded view of the system folder? Thanks in advance.--Anchoress 14:04, 9 August 2006 (UTC)

You can select what folder is displayed using a shortcut such as "%SystemRoot%\explorer.exe /n,/e,D:\Data" -- SGBailey 07:33, 11 August 2006 (UTC)
Hey thank you very much!--Anchoress 13:56, 12 August 2006 (UTC)

[edit] Sony Vegas Problem!!! HELP!

Ok. Here's the deal.

I'm rendering my video as .wmv 3mbps...

But it stops at 89%. Everytime. It doesn't come up with any errors or anything-- It just freezes at 89%. I thought maybe its just taking its time, so I left it running overnight. Woke up-- still 89%. It doesn't wanna go past frame 4939! It doesn't have an error or anything either... it just doesn't go any further.

Anyone experienced this before? Anyone suggest something?

THANKS!

gelo 14:48, 9 August 2006 (UTC)


WTF is "Sony Vegas"? Have you compared your input file to a valid hash sum? --Frenchman113 on wheels! 16:38, 9 August 2006 (UTC)
If only there were some kind of online resource, where one could look up terms one didn't recognize. --LarryMac 18:52, 9 August 2006 (UTC)

[edit] Using wireless router as wireless card

I have a desktop. I don't want to buy a wireless card for it. I need a hub/router for the extended future. Is there a way to connect my desktop via ethernet to a wireless router and then connect to another wireless router in the building? (essentially using the router as a wireless card)


This is possible. Look through your router's manual and configure it to only connect to other access points.--Frenchman113 on wheels! 16:35, 9 August 2006 (UTC)

Give them static IP addresses (in the range 192.168.x.x) and disable DHCP. Then, if you want to refer to them by name, you'll need to add entries to the \windows\system32\etc\hosts (going from memory on that path) for each computer. However, using just IP should be fine. --Kainaw (talk) 17:36, 9 August 2006 (UTC)
For reference, the correct to the path of the hosts file is C:\Windows\System32\drivers\etc\hosts.--Frenchman113 on wheels! 19:32, 9 August 2006 (UTC)

[edit] bad hub??

Hooked up three XP PC's on an old hub of mine that has worked well in the past. They all got limited or no connectivity, I couldn't access their shared files (i.e. \\comp_name) didn't work, but oddly enough we could still play networked games.

When I did an ipconfig /renew I got some message about DHCP or soemthing? I'd like file sharing to work....any idea?

All you systems are looking for DHCP addresses, but there isn't a DHCP server on the network - so they're all left with autoconfig addresses, which is what that "limited or no connnectivity" means. The easiest thing to do is to manually set their IP addresses (to 192.168.0.1, 192.168.0.2, etc.) and set the subnet mask to 255.255.255.0. Then they'll all see one another. -- Finlay McWalter | Talk 21:36, 9 August 2006 (UTC)
  • I think NetBEUI and TCP/IP are independent of each other. Assigning IP addresses will have no effect on file sharing.
    1. You need to have NetBEUI, Microsoft network client, and Microsoft network file and printer sharing installed in the Properties of your local area link. Your mileage may vary; tested with computers running Korean Windows.
    2. You need to be running appropriate services, such as "Server." --Kjoonlee 23:38, 9 August 2006 (UTC)

[edit] Boot floppy for Windows XP won't recognize an NTFS volume

Is it possible to make one that can access NTFS partitions on the hard disk ? StuRat 16:24, 9 August 2006 (UTC)

You can get read-only access with the NTFSDOS device driver described at [1]. If you want write access (and are brave) then new versions of Knoppix come with Captive NTFS, which (after some work) would allow you write access (having booted from the Knoppix CD). But Captive NTFS sounds a tad scary to me, so don't use it on anything vital, lest it get chernobylised. -- Finlay McWalter | Talk 21:45, 9 August 2006 (UTC)
Thanks for the info. Can you tell me why this is so difficult (I would have expected it to work automatically) ? StuRat 23:35, 9 August 2006 (UTC)

[edit] Task Manager (Windows XP SP1)

I have windows xp sp1 and I cant access the task manager by pressing ctrl+alt+del. A message says that it has been disabled by the administrator but I have not done that. I was wondering if you could help.

Thanks —The preceding unsigned comment was added by 82.163.35.173 (talk • contribs) .

A lot of viruses disable the task manager and the registry editor. Run a full system scan with a fully up-to-date virus scanner. CaptainVindaloo t c e 17:35, 9 August 2006 (UTC)


Thanks, but I have already done a few virus scans using Kapersky (which comes with System Mechanics 6) and the problem persists. —The preceding unsigned comment was added by 82.163.35.173 (talk • contribs) .
It might be not detecting the virus. Stealth viruses are tricky blighters. See if you can access the registry editor; go to Start -> Run -> 'REGEDIT'. If the registry editor doesn't start, and of course, you are logged in as the administrator, then you probably have picked up a stealth virus. Have you ever been able to use the task manager on this PC? And why have you not upgraded to Service Pack 2? CaptainVindaloo t c e 20:52, 9 August 2006 (UTC)
Thanks again! I will try that, when you say administrator, do you mean any user with administrator rights or the 'OWNER' user. The task manager has been working up until a few months ago. i have not upgraded to service pack 2 yet because i still have to update some of my drivers from the HP website. 82.163.35.173 21:33, 9 August 2006 (UTC)
Any user should be able to access the registry editor and task manager unless the 'owner' user (the administrator) restricts their access. The administrator should have unrestricted access to regedit/taskman at all times. I recommend that you upgrade to Service Pack 2 as soon as possible, although it is not a panacea, and occasionally causes problems itself, it may close up some of the vulnerabilities in Windows. I'm trying to find a guide to reenable regedit/taskman if a virus has disabled them, because I've been lucky and never needed it myself. CaptainVindaloo t c e 02:52, 10 August 2006 (UTC)
(New) Ha all, I have a question related to the topic, I think my hp laptop (windows xp sp2) is defected by some virus, although I have formatted it, I still get some unusual errors, such as cant save the webpage, sudden logg offs........I have tried running registry editor suggested by CaptainVindaloo after logging in as administrator,I got an error message saying that It is disabled by administrator,and after that the laptop shut dowm, just wondering does that mean my laptop has a stealth virus, if yes, what should I do, please advise me. —The preceding unsigned comment was added by 82.194.62.22 (talk • contribs) .
You probably have picked up a stealth virus somewhere. Not having physical access to your computer, the only thing I can recommend is using a virus scanner. Make sure it is fully up-to-date, and your copy of Windows is fully updated. CaptainVindaloo t c e 16:47, 13 August 2006 (UTC)

I can access the Registry Editor but I cant access the Task Manager, does anybody know what to do? Its me again (the first person) —The preceding unsigned comment was added by 82.163.36.124 (talk • contribs) .

If you can access regedit, then reenabling task manager should be fairly easy. Open regedit again, you will see that it is arranged in a 'tree' like structure, similar to windows explorer. The important thing to remember is: DO NOT mess about with anything in here, as insignificant as it may seem. Navigate through:
HKEY_CURRENT_USER -> Software -> Microsoft -> Windows -> CurrentVersion -> Policies -> System
There should be a value in here called DisableTaskMgr = 1. Right-click this value, select 'Modify' and change the '1' to '0'. Exit regedit and reboot your PC. Task manager should now work. CaptainVindaloo t c e 16:41, 13 August 2006 (UTC)
hi CaptainVindaloo,[the laptop person], I hav already scanned my laptop using Norton anti-virus software, but still it is not getting any better. —The preceding unsigned comment was added by 82.194.62.22 (talk • contribs) .
You may have to take it to a computer repairer to fix it, unfortunately. You could also try a different antivirus program; for some reason, certain programs do not detect all viruses. You may be able to identify which, if any, virus is present by: Start -> Run -> MSCONFIG. Click the 'Startup' tab and enter the process names into Google. There are a few sites out there that list processes, including malicious ones. CaptainVindaloo t c e 19:51, 14 August 2006 (UTC)
Thanks CaptainVindaloo for your help.

[edit] Fair shuffling algorithm in O(n)?

I thought about this over and over on a fishing trip to Lapland, but couldn't find a good answer. Is there a fair shuffling algorithm in O(n) time? "Fair" means that each of the n! possible combinations is equally likely. The best I came up with was an algorithm that swaps each element with a randomly-selected element, but I'm not sure if it's fair. JIP | Talk 17:35, 9 August 2006 (UTC)

I can't see this working. To give every outcome an equal opportunity, you cannot have the opportunity of any single outcome occure more than once. In other words, if your algorithm has 200 paths to completion (based on the randomizer) and one result occurs once and another occurs three times, it is not fair as you specified. The only true fair algorithm would be to build a permutation list (an array of every possible outcome) and then randomly grab one of those. I don't know of a permutation algorithm that is O(n). --Kainaw (talk) 17:41, 9 August 2006 (UTC)
Swaps each element with a randomly-selected element would be the Knuth shuffle which is indeed fair and O(n). Weregerbil 17:56, 9 August 2006 (UTC)
According to the article, my feeling that "swap each element with a randomly selected element" will produce a biased set is correct. You must swap each element with a random element taken from the set that has not been passed through yet - including the element to be swapped. Otherwise, it will be biased because you can produce the same permutation twice. --Kainaw (talk) 18:21, 9 August 2006 (UTC)
Um, of course the "randomly selected element" means a truly randomly selected element, including the element to be swapped. If swapping an element with itself is no problem, is the algorithm I described fair? JIP | Talk 18:52, 9 August 2006 (UTC)
According to the Knuth shuffle page, it isn't. the random element must be in the part of the group that hasn't been parsed yet, including the current element. For example, if you have elements 1, 2, 3, 4, 5 and you are on 3, you can only swap with 4 or 5, not 1, 2, or 3. --Kainaw (talk) 20:03, 9 August 2006 (UTC)
Actually, you can swap 3 with itself. It's easy to see that this (swapping 3 with 3, 4 or 5) is necessary for the shuffle to be fair; this gives you n! possible paths, corresponding exactly to the n! possible shuffles. (Isn't that beautiful?) If cards could not be swapped with themselves, not only would your computer crash on the last card, but you'd only have (n-1)! possible paths, so only covering 1 in n of the possible shuffles. However, if you were to be allowed to swap 3 with any of 1, 2, 3, 4, 5, you would have n² possible code paths; since n!∤n², some shuffles will occur more often than others. EdC 21:22, 9 August 2006 (UTC)
So, the only thing I got wrong was that I can't swap an element with an element before it? JIP | Talk 06:43, 10 August 2006 (UTC)
See also random permutation. Dysprosia 03:18, 10 August 2006 (UTC)
Yes, this is trivial. Assume we have a reliable uniform (pseudo-)random number generator, as is standard. To create a uniformly distributed random permutation of n items, we may use a specialization of the subgroup algorithm of Persi Diaconis and Mehrdad Shahshahani, described in "The subgroup algorithm for generating uniform random variables". It's an elegant application of group theory.
Within the symmetric group Sn of permutations of n items (of which there are |Sn| = n!) we can select a subgroup of permutations of n−1 items. This partitions the full group into n cosets of size (n−1)!. Select one of the cosets uniformly by choosing a representative element. Now recurse to generate a permutation of n−1 items. When we have only 1 item, return the single available permutation. This gives n random permutations that compose to give a random permutation uniformly distributed over the full group.
In practice, this reduces to a standard "deal" algorithm, as in Knuth (ISBN 978-0-201-89684-8). Here the randomly dealt cards collect at the end of the deck.
for k := n-1 downto 0
deck[k] :=: deck[random(0,k)]
One nice thing about this perspective is that it works for other groups just as well, including continuous groups like rotations in n dimensions. --KSmrqT 04:31, 10 August 2006 (UTC)

[edit] Services on WinXP

Just wondering which services I might be able to kill/disable without ever noticing a loss of functionality. I don't use my PC for any web servers or anything like that, or as an access point. But, I don't want to lose any performance. So, I'd like it if you could tell me which ones I don't need and can safely kill/disable.--Frenchman113 on wheels! 21:50, 9 August 2006 (UTC)

Format your harddrive and install linux. :) digfarenough (talk) 22:52, 9 August 2006 (UTC)
Ha Ha.. Penguins. Open Control Panel (in classic view)>Adminsitrative Tools>Services and go from there. Pacific Coast Highway (blah • I'm a hot toe picker) 00:34, 10 August 2006 (UTC)
There should probably be a guideline on the page that if a respondent can't figure out the answer, the questioner should not suggest the user install Linux. Dysprosia 03:18, 10 August 2006 (UTC)
I agree... maybe you missed the joke I was making to that effect :) But you're right, to answer the question, the essential services depend in part on what aspects of the operating system you're using. You may find a guide like this one to be helpful in deciding which you'll need and which you won't. digfarenough (talk) 04:18, 10 August 2006 (UTC)