I've been having problems for months with corrupted video drivers ("Windows Protection Error: you need to restart your computer") that I think are related to game software (There seems the primary culprit). I've gotten quite adept at uninstalling and reinstalling the drivers for my geForce FX5200 128DDR (AGP). Unfortunately, the uninstaller in this version appears to be corrupt (even when freshly extracted from the downloaded file); it hasn't worked correctly since I upgraded to Forceware 81.98 a couple weeks ago, so I've been simply reinstalling the drivers "over" the existing (not recommended by nVidia, but no other choice); that has been restoring service.

Today, I found the computer was down when I first got to it (I normally leave this system running 24/7, as it serves the printers for my home network of five machines). Starting in Safe Mode, however, doesn't allow me to return to Windows with VGA display; instead, I get a startup in what appears to be my usual video mode (either 1152x864 or 1280x960, 16 bit depth in either case, depending what I was working on) but after the wallpaper loads, the usual reconnect messages for mapped network drives don't appear (though the machine's drives appear to be available to other machines on the network) and, though there's additional hard disk activity (indicated by the HDD light), I get nothing further on screen but a busy cursor, which changes to a plain arrow after a minute or so. CTL-ALT-DEL produces the usual "close programs" dialog, but with nothing listed and a dotted box on the first blank line.

If I restart in Safe Mode and delete the display adapter from Device Manager, the system redetects the nVidia hardware and picks up the same bad drivers, and in any case the uninstaller crashes with an invalid page fault whether started from Add/Remove Programs or from the nVidia files folder. Also, in Safe Mode, right clicking on the wallpaper (should give options including Display Properties) gives "Explorer caused an Invalid Page Fault in module shell32.dll at 0167:7fcc5668" (the address varies after the colon). Based on this error message, I extracted a new copy of Shell32.DLL from the CAB files, did the same for EXPLORER.EXE, and have run IE6 repair utility. Last, I've run scanreg /restore and reverted to a version of the registry saved yesterday (the system ran normally all day yesterday, not even a driver corruption incident). None of this has helped.

Starting Windows with the "step by step" and logging results in a very short log; it appears logging is failing before loading most of the in-Windows virtual device drivers and such.

I'm reasonably sure my system is virus free; I downloaded and installed Avast! a week or two ago and it scanned without finding anything (though I've since uninstalled it because its resident services are both obtrusive and reduce system performance unacceptably). I got the newest security and functional upgrades from Microsoft Windows Update about a week ago. This system has: AMD Athlon XP 2600+, 1 GB RAM, dual hard disks (120 GB and 30 GB, larger with three 8 GB partitions and remainder as one partitition, smaller as a single partition; about 25 GB free on each large partition), geForce FX5200 128DDR (AGP), Aopen Cobra sound card; Windows lives on D drive and I have a bazillion installed programs (this system is continuously upgraded from DOS 3.31 installed in 1987, via MS-DOS 5, MS-DOS 6/6.1/6.2/6.22, Windows 3.0, 3.1, 95b, and 98 Original, now on 98SE).

The sooner the better, as always -- the system that's down is my primary computer; other machines are either my wife's or are old, slow systems kept in limited service in preference to discarding them after upgrades.

Okay, problem solved (short term): the computer is running again. After chasing stuff via Google and on this and a couple other forum boards for about six hours (and answering a problem on another thread that amounted to "find the correct drivers and install them"), I finally realized I was seeing a different form of corrupted video drivers. In Safe Mode, though I couldn't uninstall the nVidia driver, I was able to use Display Properties to manually select a different video driver, the ubiquitous "Standard PCI Display Adapter (VGA)", which then allowed me to get a restart in Windows (non-Safe Mode). Once in Windows, I was able to reinstall the nVidia driver, which has returned my system to normal (for an old and very tangled installation).

Longer term, I need to find a way to get the video driver corruption to stop; upgrading to XP would probably do it, but I've heard horror stories about upgrading systems that were already flakey -- I'll start another thread elsewhere on that.