Computer not starting

Computer not booting.

Everything tried like computer repair, system restore, memory check without success and it has virtually been diagnosed as a virus problem. Is it possible to remove the virus from this non bootable position without having to transfer hard drive to another computer? I know a windows reinstallation or system recovery would work but would avoid if possible.
I do not have this problem at moment just interested in case it ever occured.

If you cannot get a computer to start Windows because of a virus you can either:
Transfer the hard drive to another computer
Use a boot disc with an anti-virus program on it. Those PCIQ Professionals who travel long distances to visit clients will favour this latter solution.

Either way the result is not 100% satisfactory because although virus files can be found and removed, altered registry entries will not be changed. If a virus has attached itself to some other Windows program then gets removed, this can sometimes prevent a computer from starting until the registry entry that tries to load the missing file is corrected.

Where can one pick up a bootable disc with anti vrus programme on it and how can one verify that a virus is the cause of computer not starting?

several of the antivirus companies offer bootable disks for download, some based on Linux, some of BARTPE or VistaPE
However I've found noen of them work that well
Virus removal at the level you are talking of requires a fair knowledge of windows systems, and of how viruses work. You ofetn have to identify problems manually - and fix them manually bt by bit by selective deletion and replacement of files, and registry editing

To put it in a nutshell: I (and others here) can USUALLY do it, but not always. Sometimes I have to wipe the machine. And even when I believe I've got a machine clean, its impossible to be sure

I think Jon is being a tad pessimistic. What he is saying is, in effect, that it is impossible to detect an undetectable virus. If you are scanning a disk that isn't actually running Windows then all the virus scanner can do is find known virus files. If a file is not (yet) in the database then it won't be detected.

Oh, and Samuel, you can verify that a virus is the cause of a computer not starting by watching the compute start after you have removed the virus! But, as I mentioned earlier, just removing the virus without modifying registry entries accordingly can sometimes be counter-productive.

If after having tried the attempts mentioned above and computer still wont start can command promt be used from vista disk. If so what basic prompts are required or is it more complicated?

I'm confused, Samuel. You said in your first post "I do not have this problem at moment just interested in case it ever occurred.". So are we dealing with a real problem here or just a hypothetical one?

If you have a real computer that really won't start, if you have scanned it for viruses and found nothing, I would suggest your problem is NOT a virus!

If Windows is not starting, but the PC is powering up into the BIOS and trying to boot, it may not be a virus at all. Another possibility is that the hard disk has failed or is corrupted. If you can boot to a Command Prompt, you can try CHKDSK. There are also other commands to fix the boot partition, but these can be dangerous if you don't know what you are doing.