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

= February 8 =

IPv6 for XP
After reading the recent Lifehacker article on the switch to IPv6, I checked to see if my computer supported it. As far as I can tell, it doesn't. (ipconfig only shows an IPv4 address). So, I tried googling for an answer. I found a site saying, put "netsh interface ipv6 install" into command prompt, then lots of other things. http://ipv6int.net/systems/windows_xp-ipv6.html One, how safe is that, two, what else would I need to do for ensure compatibility with IPv6? KyuubiSeal (talk) 01:51, 8 February 2011 (UTC)

This seems to be all to allow compatibility with IPv6. However, I don't understand what you mean about the safety. Can you explain? General Rommel (talk) 06:12, 8 February 2011 (UTC)

Since I'd never seen or heard of that site, I just wanted to know if that command did what it said. After learning about rm -rf... kinda has me on edge. :P KyuubiSeal (talk) 16:33, 8 February 2011 (UTC)

Scam, spam, or wrong number?
So I've gotten three text messages over the past few days that I've found puzzling.

The first said that the IRS had accepted my federal tax return.

The second and third said that they had rejected it.

All said that for more information I should go to efile.taxact.com.

Now I have not, in fact, filed my federal tax return yet. Nor do I file them through taxact.com anyway — I use a completely different website (turbotax).

So what's going on here? Taxact seems to be a legit website. On the other hand, it's a text message, maybe there's some way that they've obfuscated the URL that I can't tell on my phone, and if I clicked through (which I won't do since I don't have a digital plan anyway), it would go to some kind of phishing site.

Or maybe it is just very crude spam. Or maybe someone else put my phone number in as theirs. Or maybe their system is bugging out.

Anybody have any guesses? --Mr.98 (talk) 12:58, 8 February 2011 (UTC)


 * Get to a real computer and look at the email as plain text in e.g. emacs. In my experience, there usually is an obfuscated URL at work - anything from clever to obvious. --Stephan Schulz 13:54, 8 February 2011 (UTC)


 * By text messages, do you mean SMS, MMS, email or some sort of instant messaging? Nil Einne (talk) 14:55, 8 February 2011 (UTC)


 * SMS, I believe — not e-mail, unfortunately. I can't seem to find a way to view the source on my phone. --Mr.98 (talk) 21:19, 8 February 2011 (UTC)


 * If it's SMS then I'm pretty sure WYSIWYG. There's no way you can hide URLs in SMS AFAIK at least not unless your phone has an incredibly silly implementation where it, for example interprets HTML in SMSes. Other then your proposals, it's possibly they're hoping you'll call or reply back to them where they can try an do something dodgy. It may even be possible (not sure about this but I know SMS has a concept of a reply path) that the reply won't end up back at the phone number which appears to have sent the SMS. Nil Einne (talk) 08:00, 9 February 2011 (UTC)


 * Perhaps the message actually said something with a different domain like  (though that example is owned by TaxAct, so it wouldn't work), and you read it as a legitimate URL, completely defeating the deception?  Paul (Stansifer) 14:48, 9 February 2011 (UTC)


 * Well, I e-mailed the Taxact.com people and they told me that it must be that someone just put my phone number in as theirs on accident. (Which is a little disturbing.) They've said they'll discontinue texting me about it. So I guess the answer was "wrong number". --Mr.98 (talk) 23:42, 9 February 2011 (UTC)

Ubuntu, showing thing bigger, how to disable
I am on a Ubuntu PC right now, and everything looks much bigger than normal. It seems like something for people with disabilities. How do you disable it? Hint: re-boot doesn't work... 212.169.191.85 (talk) 13:05, 8 February 2011 (UTC)


 * Have you checked to see whether it is set to the right screen display resolution.--Aspro (talk) 15:00, 8 February 2011 (UTC)


 * You got the magnifier turned on. To disable it: Install "simple-ccsm" from Synaptic. Then go to: System -> Preferences -> Simple CompizConfig Configuration Manager. And on the Accessibility tab, uncheck "Screen Zoom."


 * And yes, you have to install that package to turn the magnifier off. Quest09 (talk) 15:45, 8 February 2011 (UTC)


 * I found the screen magnifier option in System - Preferences - Assistive Technology without installing simple-ccsm (being Linux, there is certainly a lot of variation from version to version). Also, with no windows selected, pressing F5 opened that panel with checkboxes for a lot of things. However, turning on the screen magnifier didn't make it look as the questioner explained. It sounds more like he got bumped from his favorite resolution to something like 800x600. For me, that it is System - Adjustments - Screen Resolution. -- k a i n a w &trade; 15:59, 8 February 2011 (UTC)


 * Having a large default font set in the 'Fonts' tab in Preferences - Appearance could also fit the OP's description. Compiz has a full-screen zoom option, also, but it presumably wouldn't persist over reboot.  Paul (Stansifer) 20:23, 8 February 2011 (UTC)

Can high Internet traffic cause my browsing to slow down?
I understand that the more people logged into a given site, the slower it may be to receive packets from that site's server, and with very high traffic, I may not even be able to connect at all.

What I'm wondering is whether this effect also works in a different direction: if a lot of people in the United States (where I am) are online at a given time, will that affect the speed of pages loading in my browser, even if I'm looking at an obscure site that's hardly getting any other traffic? If not, what about high traffic specifically in my county? ± Lenoxus (" *** ") 16:31, 8 February 2011 (UTC)
 * Almost all ISP use shared resource models. For example 100 users, each with a 100 Mbit/sec connection, will be connected to a cable with less than 10,000Mbit/sec capacity. The ratio of the cable's capacity to what all the users' maximum is the contention ratio. As long as all users don't try to download large files at the same time this works fine. For normal web browsing, the browser downloads the current page's contents, and then does not download anything whilst you read the page. However, streaming audio/video, gaming, and downloading large programs/videos does use your connections full capacity for long periods of times. The ISP tries to make the contented cable's capacity as low as possible (for cost reasons), without making it noticeable to users. CS Miller (talk) 17:27, 8 February 2011 (UTC)
 * Thanks for answering! So basically, it comes down to whether people are putting a lot of strain on the ISP? ± Lenoxus (" *** ") 18:08, 8 February 2011 (UTC)
 * In many areas you can easily spot this effect by measuring your speed during the week, measuring it again during the weekend, and then measuring it a third time on a weekday when school has been canceled for bad weather. APL (talk) 15:40, 9 February 2011 (UTC)

Lil icons in the "List" or "Details" format directory listings
In Windows XP, under "My Computer" and using either the "List" or "Details" type of directory listing, there are tiny pictures to the left of each file. Most of them are standard little icons depending on which application is associated with it (e.g. a little page with the Firefox symbol in it for HTML files, or a little picture of a spiral-bound notebook for text files). I have a favicon.ico file that shows a tinier version of the favicon. Are there files cached somewhere that hold these tiny pictures? Where can I find them? TresÁrboles (talk) 18:05, 8 February 2011 (UTC)
 * An .ico file itself contains that image you see. --Tardis (talk) 19:00, 8 February 2011 (UTC)
 * Yes, I know that; in fact, I said the same thing above ("tinier version"). However, a text file, for example, certainly does not contain a little image of a spiral-bound notebook.  Is that image stored anywhere in the system, or is it made up on the fly? TresÁrboles (talk) 08:06, 9 February 2011 (UTC)
 * Oh, sorry; I thought you wanted to know where the tinier version was stored on disk. The "standard" icons are stored in a few DLLs: I think shell.dll holds the most common ones (or at least used to).  --Tardis (talk) 18:01, 9 February 2011 (UTC)
 * Windows can also extract embedded icon image data from certain types of special files - particularly, .exe and .dll files. See Resource (Windows) for information on how Windows works with those files.  Otherwise, you can inform Windows Explorer to use an external .ico (or other image) as the icon for a specific file, using the "file properties" interface.  Nimur (talk) 19:41, 8 February 2011 (UTC)
 * I think this is a slightly-different topic. See my response to the other user above.  What I'm trying to find out is if the little tiny pictures that appear on the directory listings are held somewhere on the system to be used by Windows XP, or are they just generated when needed and thus do not exist as actual files?  TresÁrboles (talk) 08:06, 9 February 2011 (UTC)


 * They are usually stored in one of the folders associated with each application. If you click on Start > Search and look for all *.ico files you will see where they are.--Shantavira|feed me 10:20, 9 February 2011 (UTC)


 * It sounds like you aren't getting the answer you want, so let's break this down as far as possible. At any given instant, if you have a Windows Explorer window open and viewing a folder full of files, you see a bunch of file icons.  Some of those icons are "on disk" and some are "in memory;" originally, everything came from disk in one of three possible locations: (1) from an embedded resource in the file; (2) from a linked .ico or other resource file that Windows is aware of because the folder saves metadata; or (3) if no other resource is available, Windows will select a "default" icon from a Windows shell file, such as shell32.dll, based on meta-data parameters like the file-extension.  So, for example, a text file that ends in ".txt" is a "known file type" and Windows uses an icon from (something like) c:\windows\system32\shell32.dll that contains thousands of "known file type" and other types of icons.  (The explanation may get very technical from this point forward).  (Make sure you understand paging and the meaning of <tt>Pagefile.sys</tt> before reading any further).  Depending on the little "picture" in question, the actual "icon" may be located in different places, including on disk, in a separate .ico file or inside the file that it refers to; it may also be dynamically generated; and it may be stored in the Thumbs.db file (if the folder is identified as a "Pictures folder" based on Explorer.exe's heuristic); any of these data may be resident in memory or loaded from disk.  Explorer.exe resides in main memory at all times (it is one of the few processes that will never be paged to disk in most Windows operating systems).  It contains a bunch of internals that are proprietary, so we don't really have access to how they work, but it's reasonable to assume that for every open folder, explorer.exe it contains a data structure to represent the folder on-screen (depending on your version of Windows, that would be one or more HWNDs that point to container content, managed by explorer shell processes).  Those data elements may be resident in the data area of RAM that is owned by explorer.exe or its associated shell extension DLLs, (which might resident in RAM or paged to disk).  Depending on whether you rebooted, hibernated, or suspended your computer, and whether the files are "new" (Windows has never seen them before), Explorer.exe may already have pre-cached the resources for the folder; this will determine whether the following metadata that I describe is resident in memory or must be pulled from disk; so these resources may be in the file or in the page file, or in RAM, depending on when you last rebooted (relative to the file creation).  Depending on what folder is being loaded, shell services may choose to reload file contents from disk and regenerate in-memory representations of the compiled resources (the icons), by analyzing the individual file and folder metadata.  Then those resources are rendered to a frame buffer; depending on your graphics driver and other system details, that "little picture" will be rendered (usually as a bitmap) to a special memory location, and then drawn on screen at your display device (your monitor, your plotter-printer, your network-attached display-emulator, your debug-dump signal analyzer, or whatever else Windows thinks is a "Display Device" attached to your "Display Adaptor".   Nimur (talk) 19:45, 9 February 2011 (UTC)

Launching a Website.....
Hi.. I have just planned to start a website... I have not developed it yet. I know I will have to go to a website hosting company. I am confused that will I have to register my website with government also or not? actually I want to develop a website in which users will be able to change the content of it ... for example as on wikipedia.. so will my web hoster provide me this service or not.? —Preceding unsigned comment added by 220.225.96.217 (talk) 20:09, 8 February 2011 (UTC)


 * You'll need a wiki software to host a wiki. You can have your page hosted for free at Wikia (check: Wikia).Quest09 (talk) 20:26, 8 February 2011 (UTC)


 * If you want a domain name of your own, (like  or  ), you need to get it through a domain name registrar.  Registrars report to ICANN, a nonprofit that is considered the final authority on domain names.  I don't know of any countries that require their citizens to register websites with their governments, but places that censor their Internet might.  Paul (Stansifer) 20:32, 8 February 2011 (UTC)


 * 1. Registering a website. You should not need to register it with the government. You buy a domain name from a registrar, and you can "point" it at your hosting company's servers. It is not very hard. I recommend getting a hosting company first because they will often give you a free domain name as part of the deal, or at a discounted price.
 * 2. Getting a hosting company. The hosting company should not charge you any differently based on whether users are able to change the content, but you will need a company that supports the server-side scripting and database architecture that such capability usually involves. So if you were hosting MediaWiki, your hosting company would need to give you access to a MySQL or PostSQL database, and would need to support the scripting language PHP. On some hosts, these kinds of "perks" cost a bit more money than the more basic options. Depending on how much bandwidth you expect the site to have, you may need to purchase a plan which accommodates for that as well (if you are just editing text, that is very low bandwidth; if users are uploading photos and movies, that is very high bandwidth). --Mr.98 (talk) 21:35, 8 February 2011 (UTC)

Got a problem with my mouse pointer-arrow
I am having problem with my mouse pointer since last one month. normally it runs very well and then suddenly it stucks at a point and it stucks so badly that nothing can move it from it's place and I have to restart my PC to make it working again I don't understand that I have problem with my mouse hardware or it is due to some kind of software problem in my OS. I am using logitech mouse and keyboard and windows 7 ultimate OS. —Preceding unsigned comment added by 220.225.96.217 (talk) 20:23, 8 February 2011 (UTC)


 * If I were debugging your computer, I would try to narrow down where the problem is. Start by borrowing another mouse (any mouse) and see if the problem goes away immediately. If it does, it's an obvious mouse problem (maybe hardware, maybe drivers, but definitely related to that mouse). If it doesn't, then it doesn't have anything to do with the mouse at all and you can start trying other things. (For example, does it happen when the computer is in Safe Mode? If not, then it's something to do with software that loads after the computer starts up. If so, then it might be something more fundamental with the operating system or computer itself.) The whole trick of diagnosing the problem (and thus fixing it) requires systematically going through and eliminating all of the obvious possibilities. It's going to be hard for us on this end to know what the problem is unless you do these kinds of things. --Mr.98 (talk) 21:31, 8 February 2011 (UTC)


 * One common cause is another pointing device which interferes with the mouse. Do you have another mouse, digitizing pad, touch pad, etc. ?  If not, you can try reloading the mouse driver. StuRat (talk) 23:04, 8 February 2011 (UTC)

Interactive guides
Hi, id like to make interactive guides such as the ones on http://va.zensupport.co.uk/ but im not sure where to start, can anyone tell me which program i should use for it? Or any other help. Joneleth (talk) 20:28, 8 February 2011 (UTC)

Is there a way to disable F5 in Firefox?
I'm using Firebug to debug my JavaScript and I keep accidentally hitting F5 to resume execution because that's what F5 does in Visual Studio. I'm wondering if there's any easy way to disable F5? A Quest For Knowledge (talk) 22:11, 8 February 2011 (UTC)


 * One way is to pry the key off. StuRat (talk) 23:01, 8 February 2011 (UTC)


 * I don't know of a way to do it directly (I checked about:config and didn't find anything promising), but if I had your problem I would just create a little widget for my task bar which would turn F5 on and off globally. I'm sure Windows has some similar key-mapping facility. --Sean 16:16, 9 February 2011 (UTC)


 * The keyconfig extension allows you to do that, although the download link given on that page appears to be having database problems at this moment. You can download it directly using this link, though. (Remember, the use of third-party extensions is to be done at your own risk. I am not responsible for any problems that may result from installing it. "It works for me" is the closest thing to a guarantee that I can give you.) -- Link <sup style="font-size: x-small;">(t&bull;c&bull;m) 08:36, 11 February 2011 (UTC)

iPhone, Blackberry, bought in one country, used in another
If I purchase an iPhone or Blackberry or iPad or Kindle (or anything similar) in the U.S. and take it back to Canada (all properly declared), can I purchase a plan for it in Canada, or does such a gadget have to be purchased in the country of principal use? Bielle (talk) 23:19, 8 February 2011 (UTC)
 * Most fancy GSM phones these days are multi-band for voice and will work in multiple countries.  Data service can be rather badly fragmented, so a 3G phone set up for AT&T in the US won't work on T-Mobile and so forth.  US and Canada use mostly similar band setups, but see UMTS frequency bands for a table.  71.141.88.54 (talk) 03:13, 9 February 2011 (UTC)

Youtube password
Is it possible to retrieve a Youtube user's password? If it is, how would I be able to do it? B-Machine (talk) 23:28, 8 February 2011 (UTC)
 * This page will let you retrieve the password for the account if you know your username or email address, and still have access to the email account you used to sign up. Youtube seems to be moving towards unifying usernames with the individual's Google Account, so you may find you can log in with your gmail details if you've previously associated the two. --  Kateshortforbob talk  00:30, 9 February 2011 (UTC)
 * This is probably irrelevant, but they allow you to reset your password, not retrieve it. Responsible websites (sadly, many websites aren't) store a hash of the password, rather than the password itself, preventing malefactors who steal the database from figuring out what the user's password is.  (Many users, after all, reuse their passwords elsewhere.)  This means that they can't tell you your password, because they have no idea; they just know what it looks like after it's been hashed.  Paul (Stansifer) 02:00, 9 February 2011 (UTC)
 * Ideally a responsible website shouldn't just store the hash but using some salt (cryptography) to reduce the risk posed by rainbow tables. Sadly many don't. Of course if you have a weak password it won't help. Nil Einne (talk) 07:52, 9 February 2011 (UTC)
 * Theoretically, even a responsible website could tell you what your password was, because they know the hash function and salt. They choose not to, which is smart, since people re-use the same passwords pretty regularly. --Mr.98 (talk) 13:42, 9 February 2011 (UTC)
 * If you use a weak password perhaps... Or if they use a totally crap hash. Or if there's a rainbow table for that hash+salt with your password. But I would argue both the later call in to question the 'responsible website' part. Otherwise I don't think it's just a matter of choosing not to, no website is going to spend months or years trying to brute force your password so they can tell you what it is, particularly since depending on a number of things, there's a far chance you could be dead before they work it out and in any case you very likely wouldn't care by that time. They could of course tell you the hash function and salt and let you try to brute force it yourself. Nil Einne (talk) 14:06, 9 February 2011 (UTC)


 * How? There are an infinite number of passwords for a given hash value. --Sean 16:18, 9 February 2011 (UTC)
 * Hash values tend to be a lot longer than passwords. A pigeonhole argument suggests that most hash values correspond to no more than one (and usually zero) short passwords.  So the shortest input that works is probably the password that the user knows.  Not that it matters at all.  Paul (Stansifer) 14:04, 10 February 2011 (UTC)
 * Good point, yes. I should have remembered that. It's a bit worrying, actually, that some websites will quite happily send you your password in plain text and says bad things about their general attitude to security and privacy. Google isn't one of these, though.-- Kateshortforbob talk  16:12, 9 February 2011 (UTC)

Pre-installed Windows without CD
When you start a computer for the first time, it starts the installer of Windows 7 (which is in the HDD). No CD is shipped. My questions are: where was this Windows version? In a separate partition or in the same of the installation? And what if you want to re-install this pre-installed version? Can you complete wipe the old installation and re-do the pre-installation? Quest09 (talk) 23:31, 8 February 2011 (UTC)
 * The last two laptops I bought both had Vista pre-installed, and on a separate partition (usually a <10GB partition). When reinstalling Windows I have just booted from that partition. I put Windows 7 on one of these laptops recently, and as far as I can see it has wiped the old Vista pre-install partition. -- <font face="Freestyle Script" color="blue">KägeTorä - (影虎) (TALK) 01:30, 9 February 2011 (UTC)
 * Aside from an actual reinstallation image on a separate partition, some computers ship with a basically installed version of Windows that has a small amount of remaining auto-configuration left to do, which may appear like an installation to some. ¦ Reisio (talk) 01:36, 9 February 2011 (UTC)