Wikipedia:Reference desk/Archives/Computing/2009 September 1

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September 1

Browsers loading blank pages

I am on Windows XP. My internet has started acting up- no matter what browser I use (firefox, IE, opera), it will start loading blank pages, with no error message at all. I can switch from an ethernet cable to a school computer network, and that will fix the problem for some period of time, but eventually the pages will come up blank again and I'll have to switch how I am connected. What could be causing this? 149.169.58.200 (talk) 04:00, 1 September 2009 (UTC)

Could be caused by a bazillion things. Try a different network cable. Try a different network outlet. Use a LiveCD to boot into Ubuntu and see if the problem exists there. Try a system restore, if the issue is recent. Try a full Antivirus scan with a decent product. And above all else, if there is tech support availible to you on-site, use it. To diagnose it in this way might be very difficult...--inks^T 04:10, 1 September 2009 (UTC)

Fine, fine, there are plenty of people who I can take it to. 149.169.58.200 (talk) 04:20, 1 September 2009 (UTC)

I would want to find out if I'm actually connected to the internet. If the problem occurs, open a Command window (Start, Run, cmd) and see if you can ping Google (type "ping www.google.com" into the command window). If it responds with something like "Reply from 209.85.227.147: bytes=32 time=38ms TTL=240" you're connected and something else is the problem. If it doesn't respond that way, you need to find out if you have a proper IP address. Type "ipconfig" into the command window and see what IPv4 address it say you have. If it starts 169. you probably have a problem, otherwise you're OK. Let us know how you go with these. --Phil Holmes (talk) 11:13, 1 September 2009 (UTC)

Try a DNS flush. From the command prompt type "ipconfig /flushdns" —Preceding unsigned comment added by Avrillyria (talk • contribs) 12:21, 1 September 2009 (UTC)

Capturing music.

I'm not a Windows kinda guy - I have a buddy who is a musician who wants to know if it's possible to capture the audio passing out through the sound card and save it to disk (preferably as an MP3 - but raw audio would be OK too). He's using various interactive performance tools and wants to capture his performance digitally.

I kinda suspect that this would drive a hole through DRM - so I suspect it's been made impossible in Windows...but maybe not.

SteveBaker (talk) 05:05, 1 September 2009 (UTC)

Yes, it entirely possible through Windows, and ability to circumvent DRM is nothing illegal or fishy in itself. To get the output, you need to go change your input device to 'Stereo Mix', 'What U Hear', or something else (varies between cards, every one I've had has been Stereo Mix). — neuro^(talk) 06:15, 1 September 2009 (UTC)

(after EC) - Yes, it is easy enough. A variety of WinAMP plugins can do this, including a disk-writer that is installed by default with WinAMP and its variants; I believe a few Audacity plugins can do this. Are you hoping to intercept audio data provided by an external program? Depending on your soundcard, the Stereo Out Mix is available as an input to record (it acts just like a microphone or line-in - except that it's the output from the system's software mixer). However, your audio driver must support that feature (it's hardware/driver specific). If this is not available on your system, possibly the easiest workaround is to use a short 3.5mm patch cable, and actually pipe the line out back into the line-in and record that way (true analog - and potentially introducing non-negligible quantization and EMI noise, depending on your needs for exact signal reconstruction and fidelity). Your musician friend will probably soon learn that Windows' audio drivers are horribly laggy compared to Linux ALSA or JACK. The standard latency can be upwards of 0.5 seconds (if he's looking for a delay line effect, he's got one for free!) This is generally unsuitable for professional-grade audio performance. If your friend is particularly technically savvy, the ASIO4ALL driver has been ported to Windows; it should allow low-level snatching of the audio buffer as you hope (and in a linux-familiar way); but I've had minimal luck with it, and its claims of exact bit reproduction are exaggerated at least - it creates terrible artifacts on my laptop's audio system. Nimur (talk) 06:20, 1 September 2009 (UTC)

@Nimur, if A4A is artifacting, have you tried increasing the audio buffer length? — neuro^(talk) 06:28, 1 September 2009 (UTC)

Yeah, I played with it for almost a week before giving up. I may give it another shot at some point; but I've concluded that JACK and ALSA are the preferred system for real-time audio on a personal computer. These run seamlessly on Linux. Nimur (talk) 06:40, 1 September 2009 (UTC)

Regarding "it's been made impossible in Windows" - that's true, and not true, depending on OS and media. ME and XP feaure "secure audio path", which allows an infrastructure of known media players and signed audio drivers to interact, which prevents recording the stereo mix of such apps, and allows the apps to verify that the audio device really is signed (otherwise one can just write a trival audio device driver and have it record the raw samplestream to a file). This could still be circumvented, with some effort, because ME and XP allow unsigned code to run in kernel space, so someone could still interfere with that secure path. Vista replaced that with Protected Media Path; it tries to do yet cleverer things, and kills DRM media altogether when untrusted kernelspace code is running. This all only applies if the app playing the code requests a secure channel using the windows media API - if it just plays regular audio down a regular audio device, then it should still be capturable (but then I don't have a Vista or Windows7 machine to hand, so I don't know that's true in practice). -- Finlay McWalter • Talk 11:16, 1 September 2009 (UTC)

If you're thinking "ah, I could still subvert that mechanism by intercepting the basic platform loader while the OS loads, and patch it to allow unsigned code (or report unsigned code as signed)", then you're right - you're essentially rootkit-ing your own machine. It's for this very reason that media owners really would like the OS to be verified by Trusted Platform Module, which would prevent anyone (even if you have root access, and full physical access to the system) from successfully patching and running a Windows 7 install. -- Finlay McWalter • Talk 11:22, 1 September 2009 (UTC)

How to turn off automatic numbering of lists of paragraphs in Open Office Writer

When I'm writing a letter or report and I want to number some points, this automatic numbering causes great problems with crazy formating and weird numbering and takes a long time fiddling with it to try and make the letter look neat and sane again. How can I turn it off, preferably pernamently please? 78.144.246.12 (talk) 14:31, 1 September 2009 (UTC)

You can select the whole document, and then select default formatting - either from the formatting toolbar, or from the formatting toolbox (F11 to open it) - If you are numbering things and want to change back to normal - just select "default" from the lists in these things at the point in the text you want the numbering to stop. If this doesn't cover it read the rest below:

Right click on anywhere in the text you are getting numbering, from the list select "Edit Paragraph Style" - a box appears.. Select the "Outline and Numbering tab" - then in the section "Numbering/Numbering style" select "None" from the drop down list.

If you have different paragraph styles which you are using, and they are all doing this - the way to fix is press F11 to make the "Styles and Formatting box" appear, in this box select "Paragraph styles" (at the top the icon like a backwards P" - then you should see a list of all the different styles. (Selecting "Hierarchical" from the drop down box at the bottom may be a good idea) - you can then right click and select "modify" on each sytle - and fix as above.

Here it's worth noting that modifying a style affects all the styles nested beneath it ie the styles that appear under the + button - as found in a directory listing in a disk system - so edit to top styles - ie default , heading etc and all sub-styles should fall into line..

I should ask that you check that the style you have currently selected is "default" and you haven't selected a queer list style by accident.. ie "view","toolbars","formatting toolbar" - make sure it is visible - then in the right box - you should see the current style - change this to default if it isn't already. (This is really the first thing to check)

Ask if you get stuck - I'm assuming that something hasn't gone wrong with it.83.100.250.79 (talk) 16:41, 1 September 2009 (UTC)

It is possible to do numbering in open office - though first it's best to format a numbering style fully to get it the way you want it - also helpful to remember is TAB to add a sub number eg 1 change to 1.1 , and shift-TAB to go back. If you get a number and you don't want it (ie after newline) just press delete and it's gone - (to get a second un-numbered paragraph within a numbered section)

Unfortunately I don't know of a good tutorial for this topic - there are some out there (search "open office numbered list tutorial") - it took me a while (day) to get the hang of formatting. I can't help thinking it could be made easier...83.100.250.79 (talk) 19:36, 1 September 2009 (UTC)

GUI Design

How can I create a Graphics User Interface in C ? One way i know is by using the graphics.h header present in turbo c/c++ (old version) which is not available in newer C compilers...please suggest some way to do this... —Preceding unsigned comment added by Piyushbehera25 (talk • contribs) 17:52, 1 September 2009 (UTC)

The Windows API itself (the underlying C API) has extensive calls for GUI programming (you get them, at first instance, from windows.h). A lot of people use Microsoft Foundation Class Library, the main C++ wrapper for those calls. These both give you access to Windows' own GUI system, which means you get programs that compile and run only on Windows. Alternatively, you could choose to use a cross platform toolkit (e.g. GTK+, Qt, wxWidgets, or Tk) - these will allow your code to work on a variety of platforms beyond windows, but you lose some of the nitty-gritty access to lower-level windows features. -- Finlay McWalter • Talk 18:19, 1 September 2009 (UTC)

Glade + gtk is a relatively easy and portable way. --91.145.73.98 (talk) 19:05, 1 September 2009 (UTC)

Thanks...can you also suggest some books or online resources which provide good coverage of the above stated api's..

gtk tutorial. If you decide to go with gtk, you likely want to install devhelp with gtk documentation. --91.145.73.98 (talk) 19:17, 1 September 2009 (UTC)

What is the current gold-standard text for Windows C programming?

In answering the #GUI Design question, just above, I was going to recommend Charles Petzold's classic Programming Windows, but I see that it's still on its 11-year-old fifth edition, and is two or three major Windows revisions out of date. wikibooks:Windows Programming#Further Reading doesn't cite anything that much newer. Is there a well-regarded book that has taken the space occupied by Petzold, or is the space left to those horrid books that charge you £40 for a printed out copy of the library docs? -- Finlay McWalter • Talk 18:28, 1 September 2009 (UTC)

I would suggest going straight to the source: Technical Resources for .NET from Microsoft. They also provide a free version of their Visual Studio .NET compiler and integrated development environment, which has a C, C++, and C# compiler (among others); and supports their newest CLR/.NET framework (and, if you prefer to use outdated technology, also supports raw Win32 api and MFC code, too). The Tech Resources on their website include tutorials, sample-code, and API documentation. This tool has a huge amount of in-program documentation as well. .NET Framework Conceptual Overview may be the best first-place-to-start, as it lays out the newest suite of technologies and how they interplay on a modern Windows operating system. (Oh the days when you simply "compiled" C code! Not anymore! Even a "compiled language" is often really an interpreted, virtualized, managed application technology suite on pretty much all of the major distributions of all the major operating systems!) These tutorials might bring the "newbies" up to speed and the "old-fogeys" might want to brush up on which of their assumptions have become invalidated by modern software engineering architectures. Nimur (talk) 18:34, 1 September 2009 (UTC)

If modern technology is so great, why are you recommending object-oriented imperative programming languages? C and C++ are both a lot older than Win32, and C#, while it's a newer design in the narrowest sense, doesn't have any ideas in it that are less than 40 years old. At least recommend F#—though I suppose its history is just as long. And were you planning to display any windows, or create any files, or open any TCP sockets to send any SQL queries to any relational database servers in your modern .NET application? Anyway, I'm pretty sure Finlay McWalter meant Win32 specifically. To which the answer is... I don't know. I would probably go with Petzold, the online MSDN documentation, and whatever other online resources you can find with a web search. -- BenRG (talk) 00:52, 2 September 2009 (UTC)

I'm not endorsing anything in particular, and I wasn't intending any descriptions in my earlier post in a pejorative way. I'm just proposing that modern C++ is dramatically technologically different from C++ in 1990; the best resource(s) for learning it are directly reading the documentation provided by the compiler and operating system vendors. The OP wanted information about "Windows programming", and the Windows API is presently defined in terms of the Common Language Infrastructure, which will probably persist beyond any specific compiler technology or GUI API. I expect that the win32 API will also soon be deprecated; we're now more than 15 years past "Windows NT" (which was intended to be the Win32 replacement). Continuing to program in that paradigm is a surefire way to keep your code non-portable and rapidly-deprecated. The conceptual ideas for modern architectures do have histories dating back as far as you want to chase them; but it's only in this decade that dynamic thread scheduling, multi-core systems, kernel virtualization, file-system-in-user-space, driver management frameworks, and JIT runtime environments have become available on mainstream consumer devices. Every single one of these technologies, which are now a crucial part of the Windows platform (and Linux and Mac OSX and others) have historical precedents dating back at least as far as the System 360; but now that they operate on every computer, the best way to learn to program these architectures is to use one of the more modern incarnations of the languages you mentioned, like CLR, .NET, or Java. All of these technologies are well-documented online via their official distributors. It has been my experience that no textbook has been able to keep up, editorially, with the online documentation. Nimur (talk) 03:27, 2 September 2009 (UTC)

Flash player on IE

When I use IE 8 to go to youtube, it tells me that the latest version of Adobe Flash isn't running, or else I have Java turned off. As far as I can tell by looking at my internet tools security levels, everything looks fine. It runs fine on Firefox. Any help? I had some malware installed yesterday (fast browser search, DO NOT install it!!!) and went through a lot of hoops to remove it, lots and lots of steps, I can't even remember all of the things I did to get rid of it, it's persistant. Who then was a gentleman? (talk) 21:13, 1 September 2009 (UTC)

Is it enabled? Tools >>> Internet Options >>> Program Tab >>> Manage add-on options button >>> Filters >>> Add-ons that run without requiring permission >>> Select Shockwave Object >>> Enable button at bottom. -- Mentifisto 21:22, 1 September 2009 (UTC)

I don't have a Filters. I have "InPrivate Filtering", which has nothing in it. I also have "Toolbars and Extensions", which had "Adobe PDF Reader Link Helper" disabled, but that's the only Adobe application there. I can't find the Select Shockwave Object anywhere. Who then was a gentleman? (talk) 21:27, 1 September 2009 (UTC)

Ah, wait. There was a drop down box which had "Run without permission" as one of the selections. That brought up several add-ons, one of which was Shockwave Flash Object, and that was disabled. I've enabled. Thanks, let's see if that helps. Who then was a gentleman? (talk) 21:28, 1 September 2009 (UTC)

Setting background picture in Windows

Hello, I have noticed that setting a picture as my background in Windows does not work very well. I am guessing the reason is pictures have much bigger file sizes now. Does this make sense? What I am saying is, whether I choose Center, Tile, or Stretch, it looks weird. For a picture I am working with right now, Center and Tile show just a small portion of the picture (though different portions) and Stretch fits it to the screen but then it is not proportioned correctly. None of these are helpful. So, is there some way to fix this that isn't too complicated? Thanks! (Oops, it might be important to note I have had this problem in XP and Vista.) StatisticsMan (talk) 21:38, 1 September 2009 (UTC)

Stretch is usually the best thing, but you need to have the image be the same aspect ratio as your screen - otherwise the stretch has to dilate it more in one dimension than the other, which produces the unwelcome distortion you're seeing. So either you should crop the image down to the same aspect ratio as your screen (using a graphics program like Paint.NET, Gimp, or Photoshop) or change to a different picture that does have the same aspect ratio. -- Finlay McWalter • Talk 21:41, 1 September 2009 (UTC)

For example, Wikimedia Commons has two categories for featured pictures that might be suitable for use as a desktop background - commons:Category:Commons featured desktop backgrounds for 4:3 aspect ratio screens (most CRT montors, and some LCDs) and commons:Category:Commons featured widescreen desktop backgrounds for widescreen monitors (which are much more common now that a few years ago). -- Finlay McWalter • Talk 21:45, 1 September 2009 (UTC)

Okay thanks. But, the picture I am trying right now is a vertical picture so it is pretty much impossible to resize the picture so that Stretch is the best option. So, I would need to do Center probably to have it in the middle and a border on the left and right. StatisticsMan (talk) 21:55, 1 September 2009 (UTC)

Yep. Although you may wish to do that yourself (again in one of those graphics programs I mentioned above) by making a new image the size of the screen, and then pasting in your vertical image. That'll allow you more control than the "center" option (you could have it off centre, or have a gradient background in the large side margins, or montage in some other appropriate images). -- Finlay McWalter • Talk 22:08, 1 September 2009 (UTC)

Mobile Phone Security

How secure are digital mobile phones? I use Verizon, if that matters. Specifically, if I have to give someone my social security number and whatever else over the phone, is it possible that someone could be listening in? I looked into this a few months ago and found out there is some sort of encryption but I never found anything about how good it is. Thanks. StatisticsMan (talk) 21:51, 1 September 2009 (UTC)

I don't believe one can get off-the-shelf monitoring equipment (the way one could with analog phones) that will monitor digital phones. The underlying cryptosystems that "secure" mobile telephony (generally either A5/1 or CMEA, depending on your phone system) are embarrassingly poor. -- Finlay McWalter • Talk 21:58, 1 September 2009 (UTC)

The most likely form of surveillance is in the form of an legitimate agency (or illicit rogue technician) who has access to the mobile telephone provider's data network. However, it's not possible to categorically exclude wireless surveillance by totally unconnected third-parties. As Finlay mentioned, the encryption on a commercial telephone system is pretty weak. Nimur (talk) 23:49, 1 September 2009 (UTC)

I always use a land-line for any sensitive data, like credit card numbers. Not that it's any more difficult to decrypt, but the eavesdroppers need to have physical access to the wires to tap a land-line, and that will dissuade almost all would-be-thieves. StuRat (talk) 13:49, 2 September 2009 (UTC)

Visual C++ Runtime Library Error

I installed a study CD from a textbook--Studyware to accompany Human Diseases secondary edition v. 2.0.0--and every time I try to run it I get this error through the path C:\program files (x86)\StudyWare - Human Diseases\Neighbors.exe and "Couldn't find Library MSVCR80.dll (require by C:\Program Files (x86)\Microsoft Office\Office12\GrooveUtil.DLL)

Help? —Preceding unsigned comment added by Hubydane (talk • contribs) 23:12, 1 September 2009 (UTC)

It looks like your system is missing the Microsoft Visual C++ Runtime Library. You can download it from Microsoft here (it's perfectly legal - it's the redistributable bit of Visual C++ for people who have 3rd party programs that depend on it). -- Finlay McWalter • Talk 23:16, 1 September 2009 (UTC)