I attempted to use system restore; no go.
I attempted to do a startup repair; no go.
I attempted a chkdsk; no go, everything was "fine".
I attempted an sfc /scannow; no go. Said some files could not be repaired and to check the log. The log showed nill that "could not be repaired".
Chalked it up to being that someone shut the computer down with the power button or the power went out and they probably had disk caching on.
Reinstalled; worked perfect after that, of course.
Microsoft had pretty much nothing on the issue. If it's any help, safe mode would boot, but not normal Windows. I thoroughly checked all services and start-up items but found nothing of significance that would hinder it--so it had to be corrupt of missing core Windows items. Along with zero viruses or spyware.