Extreme Slowness After Tons

I have been having a run of bad luck it seems lately. First, I was having tons of problems with my soundcard audio, CD burning, DVD burning, and a hard drive not being recognized. A whole thread describing that is here.This slowdown stuff started yesterday. I tried to launch an application, and Windows started to lock up. I went in to the task manager to end the process, and when I did that, the system became extremely unstable. The audio I was playing would halt and studder every 2 seconds, the mouse would freeze at the same time as the studdering, etc. I checked the CPU usage in task manager, which by the way took a long time to come up because of the extreme slowness.The CPU was not showing any high usage at all. Very low actually. After a few minutes of this, it was time to press the reset button, because it was not getting any better, and I couldn't click "Start" or reboot the machine properly from task manager.

After I pressed the reset button, Windows started booting very slowly. It would hang at the splash screen for over 10 minutes. Then the screen would just go blank. Then, I tried to start it in safe mode. Last night when doing that, it would hang at System32Mup.sys for about 10 minutes, then it would start Safe Mode and it would be fairly fast, even when doing a virus/spyware scan. (No lockups). I was describing these problems to someone I knew on IRC, and he said to check the +5V power. I quit out of Safe Mode, and went to go look for that in my BIOS. There, it did not show a +5V, only a 3 and 12 if I remember correctly. So, I booted back into Windows normally, which took the 10 minutes again, and downloaded SpeedFan. Sure enough, the +5V was showing at only an average of between 2.5 and 3.5V. I plan to order a new power supply hopefully today, but here is why I'm posting here. Minus the 10 minute hang at Mup.sys last night when trying Safe Mode, it was performing normally in Safe Mode, even while doing virus and spyware scans.