Literal computer slowdown

Two days ago my computer was fine. Yesterday my computer was fine. Today I open it up when I wake up and notice the screen is black, yet the computer is on. Okay, so it froze. I shut it down and restart it. Do a little work, it does the whole "everything is frozen but your mouse" routine. I think I might have a virus. Reboot in safe mode, start Avast, freeze. Reboot and do a scandisk thinking maybe my hard drive is shot (again), but no, everything checks out. Reboot, freeze. I figure maybe my memory is at fault.

And this is where it gets weird.

I start the memory check and set it to extended. I don't want to miss anything. I calculate that it will take about an hour and a half to finish. I leave for about an hour and get back, and it's 7% done. I thought it froze, so I press the options key to see if I'll get a response. The computer starts wiping the characters from the screen, top to bottom, left to right. I'm WATCHING my computer update the display, as if I was trying to run Vista on an Aptiva. This takes 20-25 seconds. After it finally loads the options menu I cancel out of that and restart. So I headed straight here in hopes that somebody knows what the hell is going on.

I'm running a Toshiba Qosmio X305-705. 4 gigs of RAM, Vista Premium, 2 ghz dual core processor. Has been working fine for a year now, aside from when my hard drive decided to knock the read/write head out of alignment and mock me with its clicking. I'm actually using the "broken" laptop to post this. Sometimes it'll take a few minutes to happen, sometimes it'll take 30.

EDIT: Oh, and the reason this is in hardware is because I'm fairly certain it's my processor that's causing all the problems. I'm 100% sure it's not software because it happened during an out of OS memory scan, so that just leaves hardware.

 

sounds to me like you need to let the memory test run all the way through in order to rule it out. What is your memory config? (2x2gb, or 4x1gb, or 1x4gb) . Try using only 1 ram at a time and see if it helps any.

 

Welcome to Major Geeks.
Knocked your R/W heads out of alignment? Might just now be getting worse.
Could possibly be the reason for the slow memory test.

 

The faulty hard drive was replaced long ago. This one's brand new.

Also, about the memory test. I just got a BSOD, code 9f. That and my other problems seem to suggest my fan is shot, does it not?

 

Update: Either it's not the memory, or it's both sticks with the exact same problem. I ran three tests. Both sticks, stick 2 in slot 2, and stick 1 in slot 1. All three froze at 21%. That suggests the computer can only stay at full power for a certain amount of time, which suggests, you guessed it, overheating. I'll download rivatuner or something and see if I'm right.

 

Fan's working fine. Played some TF2, got a freeze. Felt the air coming out of the fan and it was like a portal to Alaska. So it's not my memory, it's not overheating. Faulty processor? Hard drive? Does ANYBODY have any idea what's wrong with my computer?