It sounds like a memory issue.
The unit has onboard video which uses system memory.
When the memory is intensly used it could be accessing a vad part & causing the issue.
Download memtest86 http://www.memtest86.com/memtest86-3.5.iso.zip
Extract the ISO image from the zip file.
You will need a burning program , like Nero, that has the Burn image to disk feature.
Use it to burn the ymage to a disk.
[You can't just burn the ISO file to a disk like a data file.]
If you don't have a burning program with the "burn image to disk" feature download & install ISORecorder,http://isorecorder.alexfeinman.com/downloa...corderV2RC1.msi
Right click the ISO file
On the menu click Make disk, burn to disk, create disk [can't remember exact wording]
Once you have the CD made put it in the drive & boot the computer from the disk
Let memtest complete all tests at least once.
If it shows ANY errors, even 1, the memory is bad & needs to be replaced.
Memtest does not quit automatically.
I think there are 8 tests.
Once it finishes it will start over
You need to manually stop it
The easiest way is simply eject the disk & restart the unit.
OCZ StealthXstream 700W,Gigabyte GA-EP45-UD3R , E8500, Arctic Freezer Pro 7, 3GB G.Skill PC8500,Gigabyte Radeon HD 4850 OC [1GB ], Seagate 250GB SATA II X2 in RAID 0, Samsung SATA DVD burner.