Thanks for looking into it.
The CPU usage thing is new, but I can't pinpoint when it began--I've been doing a lot of fiddling trying to figure out my BSOD, and something I did must have been the starting point. But I honestly don't remember which individual item it was.
Before my first BSOD everything ran super smooth (and that's after I had updated all mobo drivers [I had not updated the BIOS yet]) and I had the most recent nvidia drivers installed at that point. Then I got a few BSOD, panicked, and started trying all sorts of things (memory checkers, driver verifier, virus scans, etc.), and at some point everything started crawling and slowing down.
When I booted into safe mode, though, to run the DDU the cpu usage problem was gone. Everything was snappy again and the garbled audio wasn't an issue anymore either. At this point should I just do a fresh install of windows? I have messed something up, but I have no idea what particular thing it is. I haven't had a BSOD again, but with the cpu usage being weird I also haven't tried anything intensive (except prime95, but only for 10 minutes).
If I do a fresh install, since I don't use any of the audio jacks from my mobo, should I not install the realtek driver, or should I just install all drivers that the mobo has listed? I had installed them all on my first install, and things worked fine (minus the BSOD), but my hope is that the BIOS update (which I only did recently) has fixed that.
Thanks again for all your help, I greatly appreciate it
EDIT also, since the cpu spiking started, it boots much slower now. Just in case that is indicative of something else going on.