Wikipedia:Reference desk/Archives/Computing/2008 December 28

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December 28

Girlfriend crashed her Mac 24.7GHz

She unplugged it while it was downloading. Stupid machine should have thought of that one. It shows lack / grey / white text that looks like MS-DOS. First word is Panic. Lots of error codes. It says to de-boot it or restart (huh?) it. When I turn it off using the power button it returns the same screen. Kittybrewster ☎ 02:17, 28 December 2008 (UTC)

Probably a kernel panic. Did she unplug it while it was installing an OS upgrade? Try reinstalling the OS with the OS media that came with the computer. -- JSBillings 02:36, 28 December 2008 (UTC)

Reset the PRAM and NVRAM first thing[1]. If that doesn't help, try a boot disk, check the hard drive. If none of that helps, try reinstalling the OS. --98.217.8.46 (talk) 04:19, 28 December 2008 (UTC)

Try booting into safe mode [2] and installing the OS upgrade again (while its in safe mode). If it was an OS upgrade. I don't see how unplugging a computer while downloading a file would permanently screw it up; it's probably filesystem corruption then (very unlikely though). --wj32 ^t/c 05:21, 28 December 2008 (UTC)

I don't know what file system OS X uses, but file system corruption can occur if the power is unexpectedly cut. The probability depends on the file system used. XFS for example, is one of those that are more prone to corruption in the event of power failure. Rilak (talk) 08:34, 28 December 2008 (UTC)

The file system is HFS+, if I'm not mistaken. — neuro^(talk) 10:33, 28 December 2008 (UTC)

Yes, and surely HFS+ doesn't use delayed allocation as much as XFS does (I use XFS)? I've had one or two power outages with XFS, but the worst that has happened is certain files I was working on got filled with nulls. You would (almost) never get file system corruption with a power outage. Unless HFS+ sucks more than I think. --wj32 ^t/c 23:15, 28 December 2008 (UTC)

24.7ghz? Hell I want that. Or is this some sort of P4 derivative? :-P We really need some of those error codes to help more. If you have a digital camera of some sort (whether phone or standalone), try taking a photo Nil Einne (talk) 11:30, 28 December 2008 (UTC)

Checking system time in batch file

I would like to know if it is possible (if so, how) to write a batch file in such a way that it executes a desired command at a specific time? Ideally it would check the system`s time (I know there`s a command that allows me to see the time, but I don`t know how to manipulate the values it gives me) and then execute my command at the appropriate time. -- 03:28, 28 December 2008 (UTC) —Preceding unsigned comment added by 89.155.228.247 (talk)

There's a command called at that does that. It uses military time. So, if you wanted to start the command prompt at 9:22 p.m., you'd type this into a batch file:

at 21:22 cmd.exe /interactive

But, as you may have guessed, you probably don't even need a batch file to run a command on a schedule. You can just type the command above.--Djnghfg (talk) 04:24, 28 December 2008 (UTC)

Deleting option from Windows boot loader

I recently installed Windows XP to a second drive within my PC to determine whether the installation was the root of an Internet-connectivity issue. Since it was not, I would like to remove the installation. I have already deleted the Windows folder from that drive, but when the computer boots, two options are still presented (a choice between booting the original installation or the newer/deleted installation). How do I restore order? Thanks ----Seans Potato Business 05:51, 28 December 2008 (UTC)

It depends on what OS created the boot loader. If it's Vista, you'd use the BCD command. If it's XP, you can open up the boot.ini file located in the root of your primary partition with Notepad. It's a hidden file, and it's read-only. But once I know your primary OS I can give you more detailed instructions.--Djnghfg (talk) 06:02, 28 December 2008 (UTC)

Thanks. The primary OS is WinXP but I have been unable to locate a boot.ini in the root of any of my partitions, neither in the GUI (hidden files made visible) nor with a CMD DOS-style prompt. My original and present WinXP installation is on the D: drive, while my recent installation went on the C: drive. However, according to the Windows Disk Management utility, C: is system and D: is boot. I appreciate any help offered. :) ----Seans Potato Business 17:08, 28 December 2008 (UTC)

That's because boot.ini is marked as hidden and system. Turn "Hide protected operating system files" or whatever it is off (it's in the same place you turned on hidden files). To actually modify the file, run: attrib -s -h -r C:\boot.ini (you can skip the previous step if you do this). Open up Notepad and change it, and when you're done, run attrib +s +h +r C:\boot.ini. --wj32 ^t/c 23:20, 28 December 2008 (UTC)

Oops, I just noticed you said D: is marked as boot. Well, change C: to D: in my instructions. --wj32 ^t/c 23:21, 28 December 2008 (UTC)

Nonetheless, the boot.ini file was on C:\! I changed the default setting and deleted the superfluous indication. Thanks very much. :D ----Seans Potato Business 10:20, 29 December 2008 (UTC)

GPRS/GSM tracking

This maybe sounds odd, but I've heard of somebody who geographically tracked another person's mobile phone by using it's GPRS/GSM signals, by only knowing the phone number. Thus effectively locating the person in question. This is likely false, or it could be done with some (possibly illegal) device? Is this technically feasable? Or there is some paid website which offers such a service? Thanks in advance. --Rev L. Snowfox (talk) 08:45, 28 December 2008 (UTC)

It's very well possible, I believe that over here (Poland) the police forces have such equipment. SteveBaker will definitely know more :) --Ouro (blah blah) 10:38, 28 December 2008 (UTC)

But I guess these kind of devices are illegal to be owned/used by civilian people (outside of military/police/other authorities), and they can't aquire these legally. I wonder if it is legal in the Netherlands...? Probably not. I know that GSM service providers (and thus police) can locate people by cell information (but that can mean a wide or narrow area too), but what I specifically heard is about GPRS data remotely being tracked, from a considerable distance (well, 1000+ kilometers). Possibly with some kind of satellites involved. But yeah, maybe it's a hoax, prank or such. I just don't know because I'm not a telecommunications expert nor a specialist policeman/military technician... But it keeps me bugging. --Rev L. Snowfox (talk) 20:14, 28 December 2008 (UTC)

This was used to assassinate a rebel leader in Columbia albeit this was with a satellite phone [3]. However you are wrong about 'just needing to know the phone number'. You really need the cooperation of the mobile service provider. Also the phone needs to be own and transmitting/receiving a signal to a base station. This may not be a problem for law enforcement agencies with warrants, but is not something some random person can do. If you install your own base stations you may be able to track a specific account but this would likely require you are able to identify the phone which again may not be possible without the cooperation of the service provider. Most GPS devices are one way. If you have something like a personal locator beacon and it's sending a signal then obviously anyone capable of receiving that signal will know where you area. Nil Einne (talk) 11:27, 28 December 2008 (UTC)

Surprisingly, it may infact not (always) need the cooperation of the mobile service provider; a few weeks ago I saw reports of an FBI system which did cellular phone tracking (in specific areas) by having special fake "cell" towers that partook of only the initial handshake part of the phone/cell connection protocol. These things would announce themselves as available cell towers, and all the phones in the area would respond (with their IMEA numbers) allowing the FBI to identify (and with a couple of diverse antennas triangulate) the location of all the responding phones. The article gave no indication as to how the FBI deployed this technology; one would imagine it would be a number of mobile units. 87.113.77.112 (talk) 17:51, 28 December 2008 (UTC)

New SATA HD for laptop

A friend of mine has bought a new sata HD for his Acer laptop, he has inserted it and when he tries to load his copy of vista on it it will not complete the installation anyone any ideas I could pass on to him thanks. BigDunc^Talk 13:16, 28 December 2008 (UTC)

Does it produce an error message? Where does it stop installing? You provide so little information that all anyone can do is make wild guesses such as "Remember to turn the computer on when installing Vista." -- kainaw™ 14:54, 28 December 2008 (UTC)

My apologies I posted before I had the full details what happens when he tries to load on Vista is he gets screen saying windows is loading files and then gets a BSOD stating:

DRIVER_IRQL_NOT_LESS_OR_EQUAL STOP:0x000000D1 or he will get this BSOD: PFN_LIST_CORRUPT STOP:0x0000004E. BigDunc^Talk 18:06, 28 December 2008 (UTC)

This probably indicates a hardware incompatibility. The KB article is 293077, but it seems like it isn't there any more. Hm. — neuro^(talk) 18:11, 28 December 2008 (UTC)

You may need to set the SATA mode in the laptop's BIOS to something like 'legacy,' 'IDE' or something other than current. After you get drivers installed (which, if using a manufacturer-provided restore set, it will do by first log in), you can revert to the 'proper' SATA mode. Washii (talk) 01:11, 29 December 2008 (UTC)

Oddly, it turns out this is what my old computer throws up now. Not used it for years, but yesterday I went to install Vista on it and it threw up a very similar situation to this. Long story short - I disabled AHCI. — neuro^(talk) 07:56, 29 December 2008 (UTC)

You may want to turn AHCI back on after you get all the drivers installed. It should enhance the performance of the system, all told. Washii (talk) 03:19, 3 January 2009 (UTC)

NNTP server software for small group message exchange

Can someone suggest a simple (meaning easy to install and manage) NNTP server app for small group collaboration? The server will be hosted locally and will not be exchanging messages with other servers. It only needs to have basic features and should not consume a lot of resources. --173.49.9.242 (talk) 15:00, 28 December 2008 (UTC)

I don't have a good answer to your question (apologies), but can I ask you a question? Why NNTP, specifically? Don't get me wrong, I love NNTP, but it's sort-of an antiquated technology, and unless you have extremely techy users, I'm pretty sure that they'd be much more comfortable with either a mailing list or a simple web forum. Almost certainly the software for those things will be much easier to install and to maintain, in addition to being much more frequently updated. There's very little semantic difference between a news-group and a mailing list.

However, just for the hell of it, I made a search in the ubuntu package database, and indeed, there are something that might suit you. See packages nntp, cnews and cyrus-nntpd-2.2. Obviously, I have no experience with any of them, but you might be able to figure them out. Belisarius (talk) 19:04, 28 December 2008 (UTC)

For collaboration, I find it sometimes helpful to preserve the discussion that lead to a decision. Many NNTP clients have good built-in threading and rule-based message handling capabilities. I find web-based message boards less easy to use and take more effort to navigate. NNTP may be dated, but it works well for hosting discussions in a friendly environment. --173.49.9.242 (talk) 01:25, 29 December 2008 (UTC)

virtual hdd images

Two questions:

1. Is there a universal virtual hard disk format that virtual box, vmware, and qemu will all work with?
2. Is there a way to convert virtual images from one format to the other, say vmware to virtual box? —Preceding unsigned comment added by 82.43.88.87 (talk) 15:11, 28 December 2008 (UTC)

This article describes how to interchange between QEMU and VmWare formats. If you get really stuck you can dd a disk from one vm to an external disk (or over a netcat to another machine or running VM). 87.113.77.112 (talk) 17:45, 28 December 2008 (UTC)

Upgrading laptop hard drive

I'm planning to upgrade my MacBook's hard drive. I don't have an external enclosure and would, ideally, like to not use one, since buying one just for this task seems a little silly to me. Is there any way to use my Firewire external drives to clone the old disk to the new disk? I was thinking of using some program like the GParted LiveCD to try and create a disk image from the old drive to the Firewire drive, then swap the new drive for the old one, then try to boot up in GParted LiveCD again and have it apply the image from the Firewire drive. Will this work? Will I run into problems with "growing" the partition from the old drive (80GB) to the new drive (320GB)? Both will be HFS+. --98.217.8.46 (talk) 16:36, 28 December 2008 (UTC)

If you have a firewire external drive, the best way to do it is to make a Time Machine backup. Then when you reinstall it again, then you can restore from the external backup. Carbon Copy Cloner (free of charge) works well to. 78.148.224.67 (talk) 20:10, 28 December 2008 (UTC)

I am using OS X 10.4 so I don't have Time Machine. CCC seems like a good program but I don't see how it'll help me here—surely CCC cannot completely clone the drive that it itself is running on? Without a LiveCD I'm not sure I see how this can work... --140.247.236.37 (talk) 21:47, 28 December 2008 (UTC)

Nevermind—I figured out a way to do it with CCC. Basically I'll 1. use CCC to make an image to my external drive; 2. install the new drive; 3. use my wife's iBook to mount the new drive in "target disk mode", and 4. install the image off of the external drive with CCC (linking to the external drive either daisy-chained with the MacBook or with a USB port). That should create no issues with having to "grow" a HFS+ drive. --98.217.8.46 (talk) 01:22, 29 December 2008 (UTC)

Actually CCC does make bootable clones, at least it did before yesterday, when it didn't - for me anyway. I've cloned ~150GB+ with it an got something bootable on an external disc. 89.242.188.116 (talk) 18:53, 29 December 2008 (UTC) This is the original answerer here, in case anyone is wondering. My IP address seems to have changed.89.242.188.116 (talk) 18:54, 29 December 2008 (UTC)

history deleted ,page visited are not available offline

when I visit pages on the internet, these are some time deleted from the history even after closing internet ,although I have adjusted history for 15 days ( from control pannel ,internet options ,setting ),what may be the problem with my computer .I have installed an antivirus norton on my computer ,is this antivirus is doing this.help me to overcome this problem —Preceding unsigned comment added by Khubab (talk • contribs) 20:37, 28 December 2008 (UTC)

Your Antivirus program wouldn't delete your browsing history. Don't disable it. Why do you need to keep your browsing hsitory? If you need to view web pages offline, save them. --wj32 ^t/c 23:26, 28 December 2008 (UTC)

Although admittedly Norton is absolutely abominable, wj32 is right. If you do suspect that it is your AV, though, you could always test by disabling it, closing, and then seeing if it is still there. — neuro^(talk) 07:54, 29 December 2008 (UTC)

There is a difference between retaining browser history (the list of pages you've visited) and retaining the browser cache (the actual contents of those pages last time you visited them). I suspect the setting you've changed only applies to Internet Explorer's browsing history, and does not automatically mark websites to be available offline.

There are separate settings that tell IE to make pages available offline, and a special "offline browsing" mode that makes sure it uses these wherever available. I believe you have to turn this on for each site (I think creating a bookmark and saying "make available offline" is one method) rather than for all sites at once, but you may have to look in the online help as I don't know the details. - IMSoP (talk) 17:59, 29 December 2008 (UTC)

no sound

I have core 2 dua processor with intel mother bord .I have installed 1:-intel(R)chippest software installation utility 2:-Realtek audio driver some days before all things are working well.but now there is no sound and no appearence on toolbar(a small speaker on tool bar) what should be the problem .and what is the purpose of installing intell(R) chippest software utillity. —Preceding unsigned comment added by Khubab (talk • contribs) 20:58, 28 December 2008 (UTC)

Windows XP or Windows Vista? Rgoodermote  21:56, 28 December 2008 (UTC)

windows xp —Preceding unsigned comment added by Khubab (talk • contribs) 00:46, 29 December 2008 (UTC)

If you go to Device Manager, do you see your sound card listed under "Sound, video, and game controllers"? Do you see any devices that have a question mark or exclamation mark next to them? --71.141.98.38 (talk) 03:21, 29 December 2008 (UTC)