Six days ago his computer crashed when he *turned it on*, and he gets the BSOD before getting into Windows, with the STOP: OxC000021a {fatal system error} The windows log on process system process terminated unexpectedely with a status of Oxc0000005 (Ox00000000 Ox00000000) The system has been shut down.
Since then I've been trying to help him. Problem is it's not easy to help over the phone, especially someone who is not as IT literate. But anyway, this isn't the problem.
The fatal error is clearly serious, and you cannot get beyond this screen, so my number one choice is somehow to get to a last known configuration. I think (it's only a hunch) that the OxC000021a has been caused by a Windows Update conflicting with a previous hotfix or update - the computer has not been shutting down (BSOD) properly for about a year. Of course, I may be wrong.
All I do know is that we need to get him into a last known config. You get to the Safe Mode boot options via the F5 key (I'd been telling him F8 for a while, but this kept coming up with Cmos and Bios settings I think, and I don't this we need to go there yet). Anyway, once we've worked out how to get to the Safe Mode boot options, you get the eight or so options - Safe Mode with Command Prompt, Start Windows Normally, Last Known Configuration, etc etc. The up/down cursor works fine.
But our problem is this. Choose any of these, eg Last Known Configuration. You then get to another screen choice, with the top (highlighted) saying Windows XP and the bottom one with the choice you have just made. But the cursor will not work. The down arrow won't work to highlight "Last Known Cofiguration" or "Safe Mode with Command Prompt" or whatever it is. He's tried the down arrow, he's tried turning Num Lock off and hitting "2" on the numerical keypad, he's tried everything. But no, it only allows you to enter XP and then, of course, it tries and fails with the BSOD and the OxC000021a rubbish). Arrrrgh! So close yet....
Basically, I'm hoping that the Last Known Configuration will work (you can't get to System Restore from Windows at the moment, as you can't get into Windows). If that doesn't work, then at least I could get him to go into the Command Prompt, and run %systemroot%\system32\restore\rstrui.exe so that we can try and restore him to five or six mornings ago, when his computer last worked. I'm sure that would work - at at least it will give him a chance to do some final backups onto CD of any of his latest files and music, just in case it happens again.
Even if that didn't work, I could get him to run Dr Watson so that we can see what is causing OxC000021a - it'll either be Winlogon.exe or CSRSS.exe (one or the other, my money's on the Winlogon) but at least we can narrow it down.
But right now, we need to be able to use the up-down arrows to highlight options AFTER choosing them from the boot options screen. If anyone can help with THIS at least, it would be a massive help!
Many thanks!
Tristán White, London, UK