ASUS ACPI not responding

Okay so ive been having problems with Windows Vista x64 for just about the entire time I've owned it...no surprise. However a new one has come up and it only seems to happen when I'm using cpu/ram/gpu intensive software such as Call of Duty 4, WOW, Counterstrike, Fear 2, etc. When this problem occurs my pc pretty much lags itself into a 0-4 fps, and when I close out the program i see "ASUS ACPI (Not Responding)" as a program in the task bar. If i try to click it it just goes away and then I have to reboot my pc before I can run any games efficiently.

2 Other problems that have been occuring that began at about the same time are 2 Blue Screen Crashes one stating the cause was "USB_DEVICE_DRIVER" and the other being "IRQL_NOT_LESS_OR_EQUAL"

Ive ran CCleaner, and MEMtest, and they both have shown no problems or errors. Also I have ran the normal Anti-virus/Anti-Spyware, and furthermore have defragged my 2 HD's. Also I have test on all 3 separate ram cards one at a time in my MOBO to make sure volatile memory is intact, and tried a different Graphics card. All of these tests have resulted in no positive results. If someone here can tell me what could cause all 3 of these problems I would greatly appreciate it. I'm fairly certain I am going to have to buy something here, but if a simple format is all that is needed then thats great news.

Here are my tech specs in case anyone needs to know them:
Windows Vista Ultimate x64 SP1
Nvidia Geforce 9600 OC
Creative X-fi Xtreme Gamer
AMD AM2 (940 socket) 5400 3.0 Ghz with 256 L1 cache and 1Mb L2 Cache
Seagate 500GB SATA
WD 320GB SATA (HD's are not ran in RAID configuration)
600W Antec Power supply
-----------------------------------
BIOS Info:
ASUS M2N32 SLI-DELUXE
ACPI BIOS REVISION: 0302
BIOS ROM SIZE: 1024kb
STARTING ADDRESS: 0xe000
CHARACTERISTICS: 0x000000007fcb9e80

MOBO Info
VERSION: 1.xx
SERIAL: 123456789000 (yes i know how stupid that sequence is but i swear to god its what it says lol)