Wikipedia:Reference desk/Archives/Computing/2011 April 8

= April 8 =

Antivirus software policy
I have Norton and notice that when something get caught, the software puts the virus into a quarantine instead of immediately deleting it. Why would someone (as in the average Joe computer user) want to keep a virus around? 76.27.175.80 (talk) 00:39, 8 April 2011 (UTC)


 * Two reasons: 1. It might be a false positive, i.e. The virus scanner thinks something is a virus that isn't. Not as uncommon as you might think. 2. The virus may have infected a file that contains useful information (e.g. a Word document) and you might be interested in later trying to extract the good information from the file before deleting it. This is more unusual, I think. In general I think software developers are a bit queasy about making heuristic software that deletes things on its own initiative — it's easy to imagine that going wrong one way or another. It is safer to just "quarantine" it and make it so that it can't execute. --Mr.98 (talk) 01:21, 8 April 2011 (UTC)


 * You can usually change the default to delete if you are confident. ---— Gadget850 (Ed)  talk 15:58, 8 April 2011 (UTC)

DS catridge data onto computer
How can I read data that is stored in a DS cartridge onto my computer? Specifically what sort of equippment would I need to use/get in order for this to work properly without severly messing up the saved data? 64.75.158.196 (talk) 03:31, 8 April 2011 (UTC)
 * Do you mean a game cartridge from a Nintendo DS? Or do you just mean a regular SD card that has been used in such? For the SD cards, any Memory_card_reader will do. For the cartridges, you may find useful information at Nintendo_DS_homebrew. SemanticMantis (talk) 17:48, 8 April 2011 (UTC)
 * The Nintendo DS variation. I'm not hacking or anything like that, I just want to rename some of my game profiles without the need to start everything all over again. 64.75.158.195 (talk) 22:50, 9 April 2011 (UTC)

Pieces of a URL
Two questions —
 * 1) The "Use in web site hosting" section of Domain name provides a URL and shows the names of its various components. Is there any good reason not to have this same feature in Uniform Resource Locator?
 * 2) As an IUB student, I can access many of its resources off campus through the library website. Whenever I do this, the websites' URLs have extra bits appended at the end — for example, I use http://web.ebscohost.com.ezproxy.lib.indiana.edu and http://www.jstor.org.ezproxy.lib.indiana.edu instead of http://web.ebscohost.com and http://www.jstor.org.  Is there a standard name for URL components that follow ".com" and ".org" in these examples?  Nyttend (talk) 04:07, 8 April 2011 (UTC)
 * URL's don't especially care about domain names. There's stuff between the // and the first / that might or might not be a domain name.
 * There's not a standard, that syntax is specific to ezproxy. 75.57.242.120 (talk) 06:16, 8 April 2011 (UTC)

We should be clear: the URL you are accessing is read right-to-left - so you aren't accessing JSTOR, you're accessing "lib.indiana.edu", who is proxying for you. The proxy-server is interpreting the subdomain (everything to the left of the top-level domain), and using that information to deliver your content. Nimur (talk) 13:37, 8 April 2011 (UTC)

PCI-E graphics cards lanes
Do PCI-E &times;16 graphics cards, no matter how low-end they are, really require all the 16 lanes for best performance? In other words, will the performance of a PCI-E &times;16 graphics card, no matter how low-end it is, decrease if it is only allocated 8 lanes by the motherboard? How big will the decrease be? Many thanks for all answers. 118.96.161.40 (talk) 14:05, 8 April 2011 (UTC)


 * PCIe allows for dynamic lane allocation. Every time you lose a lane, you lose 250 MB/s of available transfer throughput.  It's not a matter of "low-end" or "high-end" - it's a question of whether you needed that throughput for some particular software operation.  If a low-performance GPU was backed by a low-performance software driver that never fed more than 1 lane's worth of data per second, then you'd never notice any slowdown.  The same would be true if a high-performance GPU was never fed more than one lane's worth of data.  Ultimately, you need to know what the software is doing, and whether the program will gracefully scale performance to match available throughput.  Nimur (talk) 22:50, 8 April 2011 (UTC)

Symbolic links to directories, trailing slash
I've noticed that the format in which you enter a directory name is stored exactly as entered, when creating a symbolic link. Example:

nblue@pluto:/var/www/foto/RESULT3$ ln -s /home/nblue/album/Test fullsize nblue@pluto:/var/www/foto/RESULT3$ ln -s /home/nblue/album/Test/ fullsize2 nblue@pluto:/var/www/foto/RESULT3$ ls -l | grep fullsize lrwxrwxrwx 1 nblue nblue  22 2011-04-08 16:47 fullsize -> /home/nblue/album/Test lrwxrwxrwx 1 nblue nblue  23 2011-04-08 16:47 fullsize2 -> /home/nblue/album/Test/

(I'm using Ubuntu 10.10) Both links work as intended for my purposes. Are there any circumstances in which the presence or absence of the trailing slash in the symlink could make a difference, and is there any reason to prefer one format over the other? --NorwegianBluetalk 15:07, 8 April 2011 (UTC)


 * The only thing I can think of is that a program might take that directory and add another level to it (say to create a new sub-directory). A careful program would add the slash, but one that didn't would require it in the original string to work properly. StuRat (talk) 16:29, 8 April 2011 (UTC)
 * Yeah, and I'm not sure that would ever even manifest (because you still have to sub-directory the symlink). Just stay cognizant of this sort of thing, and if you see any script or program weirdness, you already know how to fix it.  Nimur (talk) 16:54, 8 April 2011 (UTC)
 * Thanks. I looked around in the system directories. The links that I found used the format without the trailing slash (e.g. lib64 -> /lib in the root directory). So I'll stick with that format! --NorwegianBluetalk 08:55, 9 April 2011 (UTC)

.iso files
I have received an .iso file from net that is about 1.5 gb. How do I convert it into a CD or DVD that I can properly use ? Jon Ascton   (talk)


 * You need a program that can write ISO files to a disc. These instructions, provided from Ubuntu, list techniques for burning ISO files to disc on all major operating systems.  Of course, use your .ISO file (not the Ubuntu disc-image file).  Nimur (talk) 16:56, 8 April 2011 (UTC)

I suggest using imgburn 82.43.90.38 (talk) 19:14, 8 April 2011 (UTC)
 * Or, you can pretend there is an actual DVD drive and so instead of having to burn it, you can just make a virtual DVD drive and put any file you want in it to make it a DVD. Daemontools or MagicISO can do that. Unless if you prefer to have it on disk. General Rommel (talk) 22:50, 8 April 2011 (UTC)
 * I like ImDisk for that. ¦ Reisio (talk) 04:32, 12 April 2011 (UTC)
 * Keep in mind that ordinary CDs don't have the capacity for 1.5GB, you will need a DVD. ¦ Reisio (talk) 04:32, 12 April 2011 (UTC)

Out of memory in XXX
This time I waited until I actually talked to someone who could do something about the situation. Unfortunately, it was so hard to find just the right person, and even then all they could do was report the problem to the right people, who I had no access to. I'm curious to know what was going on. And perhaps an answer here can help me more clearly explain the problem to those who could fix it.

It was a day when I had been led to believe the library at the college I went to would be open. It was not. As long as I was there, I went in the building where the basketball arena was located. Next to the food court was an Internet computer. I sat down for a few minutes to use it, but it kept shutting down even though all I was doing was looking at newspaper articles. On several occasions, I got a message that the computer was unable to perform the requested action, but pressing the back button merely gave me a "The page cannot be displayed" or something similar. Going back to the same article gave me the article, but the URL was the same as when the article couldn't load and gave me the "The page cannot be displayed" or whatever.

One time the computer froze completely. I mean no keys or mouse clicks would do anything. I didn't even see the endless flying of the flag with the Windows logo, which on most computers has been replaced by a rotating circle. I clicked on "Start" and restarted the Internet (shutting down was not an option since that day I couldn't be sure anyone could help me), but that frozen page remained the rest of the time I was there. At some point, the errors didn't cause a disaster, but I merely got a message saying "Out of memory in" followed by a nnumber with from one to three digits. Vchimpanzee ·  talk  ·  contributions  · 21:00, 8 April 2011 (UTC)


 * Vchimpanzee, we have tried many times to help you diagnose or at least understand what is wrong with your computers. In most cases, you need to contact the administrator of the computer (the librarian, the university I.T. department, or so forth).  Ultimately, though, it seems like we must classify the majority of your problems as "user error" problems - have you considered signing up for a basic computer and internet training class?  The frequent difficulties you are having, and your inability to describe meaningful symptoms, indicate that you might benefit from some training.  We can help refer you to a course, but we can't magically diagnose every system error you encounter, especially while your descriptions are this non-technical.  Nimur (talk) 21:27, 8 April 2011 (UTC)


 * My problems are not "user error". I'll report back if I ever track down who fixed or could fix the problems described above. I don't know why I bother to describe anything to anyone because they're never satisfied. Vchimpanzee  ·  talk  ·  contributions  · 21:29, 8 April 2011 (UTC)


 * Some of the things you need help with are basic writing skills. For example, the fact that those computers were near basketball arenas or food courts are simply not relevant.  Instead, you need to list more detail about exactly which steps you performed and precisely which errors occured.  For example, what operating system were you using ?  Windows XP ?  Which Internet browser ?  Firefox ?  Describe step-by-step, from the start, the exact sequence of events including any error messages in full. StuRat (talk) 21:39, 8 April 2011 (UTC)


 * Also, consider the way that other posters on this desk describe their problems. Try to emulate their level of detail.  We want to help people - we're volunteering out time to help others - but we need a meaningful problem-description, or we aren't able to provide a meaningful answer.  Nimur (talk) 21:43, 8 April 2011 (UTC)


 * I think the location of the computer makes it very relevant. It means there wasn't anyone around to help, and it means it's harder to figure out just who is in charge of it. The library computers are under better control because people sign in, and there are people around to answer questions and fix things.And according to one of the people I talked to weeks later wondering what was wrong with it, it meant anyone could do anything to it. I'm not saying anyone put viruses there, but this one person said that might have happened. And I did say it was a Windows computer with a flag flying.


 * I don't know how to make my descriptions any more meaningful. I can't explain it. Vchimpanzee ·  talk  ·  contributions  · 21:48, 8 April 2011 (UTC)


 * Rather than just saying "Windows", you could say if it's Windows XP, Windows Vista, Windows 7, or something else. StuRat (talk) 16:51, 9 April 2011 (UTC)

By the way, one of the first questions I ever asked was answered years later when I had a similar problem, and I saw similar information in the Hang (computing) article after the idea of a search for something popped into my head in a way it never had before.

Also, the Firefox computer where I have had some problems was recently upgraded. As to the specific problems I was having, the person who does that said it's old and there's no cure, though I suspect there's something specific happening that I just can't identify. Virus updates slow that computer down, I do know. Vchimpanzee ·  talk  ·  contributions  · 22:02, 8 April 2011 (UTC)


 * I didn't say that about "Windows". I don't know which one has the flag. I'm sitting there, in a building where I'm not sure anyone is around to fix things, going nuts because the thing keeps shutting down or being unable to complete the task and you expect me to know which version of Windows? The good news is I probably won't use this computer again. As long as the library is open when I go, I suppose I won't be having these problems. Here I thought I asked a simple question. Vchimpanzee ·  talk  ·  contributions  · 17:33, 9 April 2011 (UTC)


 * In order to discover the version of Windows, press the button, type in, and hit . Then, at the command prompt, type , and then press . You should get a message similar to  .  Rocketshiporion ♫ 00:41, 10 April 2011 (UTC)


 * This will only work exactly as you described on Vista and 7, and in fact on those operating systems there isn't technically a button labeled start. Win XP and below don't have start menu search.  I bet this computer is running XP, which can be confirmed by seeing if there is a button labeled "start" on the bottom left, if it's just the windows flag, then it's vista or 7. Chris M. (talk) 13:04, 12 April 2011 (UTC)


 * I tried that on this computer. I ended up on the Microfilm reader and didn't find out which version of Windows. Vchimpanzee ·  talk  ·  contributions  · 18:29, 10 April 2011 (UTC)