Ouch!
Like a ghost from the past. See
this MSKB article. No, I know you're not running NT 3.1. But I suspect the issue is, indeed, caused by a hardware compatibility issue of some kind. Was something new installed recently, just before the problem occurred? Had you edited the registry manually just before the problem occurred? If so, were you using regedit.exe or regedt32.exe? The other error you mentioned, in conjunction with anything you might get from the Event Viewer logs, could help you triangulate on whatever it is that's messing up your software hive. You would be looking for something in common among the causes listed in the MSKB for the various errors. Do you have any such other information?
Since you were able to recover using a repair install, and the file system and everything else seem okay, you can choose to simply re-install your software. I suspect, however, that something is present hardware-wise that may continue to farkle the system. I'd suggest working diligently to find any incompatible hardware / drivers on the system and either get rid of any culprit devices found or update their drivers so as to eliminate any possible incompatibilities.
If you haven't done so already, it's very important for you to back up your data to external media. Even if this isn't a hardware compatibility issue, it might be an incipient hardware failure.
I guess you probably will want to re-install the OS from scratch, though a re-installation of all software is a possibility. But I wouldn't do it until I found the source of the trouble. Otherwise, it's all likely to circle the drain again.
Regards,
Jim