I have had incredible problems since this afternoon. My less than 1 month old system, which was quite fast and would boot up in under 30 seconds, has slowed to a crawl. Boot now takes several minutes, and I am not certain it actually finishes as I've noticed that Steam usually won't load. Any actions (even the Start Menu) take at least several seconds to execute; some won't fire for a couple minutes. Firefox and Windows Explorer are so slow as to be practically unusable. Also, Norton Internet Security doesn't load as active (that is, the icon in the hidden icons box has a red X instead of a green Check). The Action Center program, when activated, tells me that it has been disabled; no amount of turning it on will change this.
Safe Mode works just fine; there are no performance issues there. I have attempted to use System Restore twice (backing up to configs from the 12th and then the 10th), but both attempts failed. On both occasions it told me that an unspecified error occurred (0xc0000022). Then, after restarting in safe mode yet again, it said it was successful. I also removed everything other than Norton from the list in msconfig. This did not seem to do anything. The Startup Folder contains nothing other than an HP utilities program.
I have noticed a couple of odd occurrences prior to today. A couple of days ago NetGear's wireless card program loaded like I'd just installed it. The Aero theme occasionally has reset its colour scheme as well over the past week, after I'd had system hangs that forced me to hit the reset button. There were three such events if I recall. Never thought much of any of them as things worked normally afterwards.
Windows 7 Home 64bit (Build 7600)
Core i7 3.06 CPU
Asus Rampage III Gene Motherboard
12 GB RAM (Kingston Hyper-X DDR3 1600)
EVGA GeForce GTX 470 (Fermi) 1280MB 320-bit GDDR5
Intel X25-M 80GB MLC SSD
WD 320 GB HDD
WD Caviar Black 1 TB HDD
NetGear Wireless card