Well I think I've really F-ed things up this time. I had made progress yesterday, finally being able to log into my regular account, without being locked out of certain things, despite still having some visible spyware/malware (some fake antivirus BS popping up). But it was real progress. But I decided to keep going through my long list of steps (from the link I posted last time) and the next step was running ComboFix. Part way through that scan it had to reboot, and I haven't been able to launch Windows since! Not even in safe mode. This is the suck.

I don't think I have an original XP Disc either, didn't get one shipped with my computer (but will search at home later).
I've just been searching Dell and Microsoft support for answers...nothing good yet.