Got a spare hard drive? Bootable CD? Any bootable medium more robust than a floppy?
Seems like once you get it booted from a different startup volume, you should be able to drag/copy the necessary files to the proper location until you get the original to boot. I’m a Mac person, but I would start with replacing the contents of the WINDOWS\SYSTEM directory a few files at a time, and if that doesn’t do it, go on to the surrounding WINDOWS directory (you don’t want to overwrite a parameter or settings file, but drivers and shared libraries are fair game). Also, I think Windows hides some of its crucial files by making them invisible, so you might need to check for and replace invisible files.
I just had to do this on a Mac. I don’t know how, but I managed to hose MacOS 8.6 and had to boot from a different partition and copy files. Spent hours gradually adding back in the bloody extensions and control panels until I’d weeded out the corrupted files and gotten it to run with all its original capabilities and settings.
I don’t envy you; all in all, I suspect it’s a bit easier on a Mac.