Vista x64 Slow, BSOD, Full HDD, etc.

First off my stats:

Dell
Vista x64 SP1
Intel Core i7 920
6gb ram crucial (2gb strips)
High end video card (i forgot b/c I am so stressed)
640GB HDD
(purchased May 5, 09)

Computer knowlegde - Advanced, but certainly not expert

Symptoms:
1.) Slow response times that kept getting slower.
2.) Computer not recognizing plug n play peripherals or doing so only after several minutes. (i.e. USB external HDD)
3.) Program Freezes that had to be stopped in Task Manager
4.) "My Computer" would take forever to refresh
5.) Disk A loaded in drive, eject, then load disk b, My Computer would continue display disk A
6.) Unable to do Windows update
7.) When trying to do simple tasks HDD cycles through: revving up then revving down.

I tried several things to remedy the above. Setting my power to High performance (slow response possibly linked to in and out of sleep mode). Deleted a folder in c: named with lots of numbers and letters that I was told was caused by a bad windows update. Subsequently two more appeared after two unsucessful attempts of updating. So I deleted those and said screw the updates. I did a quick scan with superantispyware and nod32. No malware, but three viruses.
I ran Raxco perfectdisk defragger - disk in excellent condition. Ran hijackthis - nothing noticeable. All my problems SEEMED to stop for a day.

Yesterday, I noticed the music skipping in iTunes. The computer locked up a few times and the only remedy was the power button. Then it happened - BSOD.

I tried safe mode - nothing - it would reset.

I tried windows start up repair - BSOD.

The only way I could get it to load was to roll back my computer using the installed Rollback RX Pro. (Safety precaution due to issues with previous computer). By rolling the computer back a couple of days it will start, however, another bigger issue has occurred. All of my disk space is GONE. The safety partition installed by Dell is full (15gb should only have 7gb used) and my main partition is full too (should only be about 50% used). I deleted over 30gb of stuff - ran CCleaner - disk still full. I immediately thought malware - tried to run superantispyware. After start up it would say initializing scan and then just close. I opened again and updated first, then same thing occurred. I ran Perfect Disk again - no issues. I ran check disk from within windows - it froze. I ran through command prompt - said cannot lock volume, then 5 minutes later asked if want to do after restart I said yes. I restarted - check disk did not load, went straight to windows. I tried to go into my account - no go. I ctrl-alt-del switch accounts to my wife's and then I tried NOD again - super slow and eventually stalled. I download spybot and installed it. When I tried to back up the registry - froze computer. Had to push power button. I estimate that this was about the tenth time that this was done over the past two months due to computer freezing up. Obviously something is bad wrong and slipping through NOD and SupAspy or possibly impending HDD failure.

I should be able to roll back the computer with Rollback RX Pro and get into windows again. Keep in mind that the process will simply restart the clock before it freezes.

P.S. Hijackthis file attached

first thing i would suspect would be bad memory, go to control panel, administrative tools, memory diagnostic tools and run the extended test and see if your memory passes. also check to see if the computer is overheating.

How do I check if overheating? I suspected that awhile back, but I don't know how to check temp. Shouldn't the pc handle cooling fans independently?

do google search for everest ultimate and download that. then in left hand window expand the computer branch and select sensors. look to see what temperature everything is running at. yes the computer should handle cooling but things sometimes do not work like they are supposed too. hence the reason you are here asking for help check for dust build up and things like that on the fans and intakes

I have traced the issue back to Rollback Rx. I uninstalled it - problem solved (mostly). I still cannot update Windows. The screen just freezes.

BTW - I dl'd everest. The temps are 40-43 degrees Celcius.

that is a bit warm for the CPU. what speed are the fans running at? everest should show that also. might check in bios to see if throttling is enabled for the cooling fans and disable it

I could not find fan speed in my bios. I dl'd speedfan and have set the temps to 37. After setting idle for a few hours, it got down to 36. Is that cool enough or should I get a better fan / heatsink? If so, please provide suggestions.

that is an ok temp but could be better. what are your temps when stressing it? that is the key. as for coolers there are a lot to choose from. i use arctic cooling for mine. if you want to spend the bucks go for some of the more pricey ones but for your use i would recommend a mid range one like mine.