Hi there i have a old post here: http://forums.evga.com/GTX-460-SC-EE-freezing-99-load-m2233702.aspx
 
I have found my problem. 
 
MY GPU is not freezing with 99% load. is freezing when my memory is on using (GPU MEMORY) (i think this memory is called VRAM)
 
ok first of all my GPU is this:
 
EVGA GTX 460 SuperCloked External Exhaust 1GB GDDR5.
 
I have tested with:
 
1. Furmarker (No Errors) (Max Temps 70C)
2. OCCT (No Errors) (Max Temps 70C)
3. GPU-Z (No Errors) (Max Temps 70C)
4. MSI Kombuster (Error, Freezing) (Max Temps 75C)
5. Clean Driver Installation and Old Drivers. (Any change)
6. Disable HD Audio Driver (Any Change)
 
 
ok i see MSI Kombuster give me an error yes? why? bcus Furmarker, OCCT, GPU-Z Only put my GPU to load at 99% but use only 168mb of VRAM. But MSI Kombuster use 600-700MB of Vram.
 
I have already tested all my components.
 
Processor: 
1. OCCT (No Errors) (Max Temps 60C)
2. Everest Ultimate Stress Test (No Errors) (Max Temps 65C)
3. Prime95 (No Errors) (Max Temps 70C)
4. S&M (No Errors) (Max Temps 68C)
 
Memory Ram: 
1. Memtest86 8 Hours 8 Pass (No Errors)
 
Hard Drive:
1. HDD Regenerator 10 hours 8 pass (No Errors)
2. CHKDSK (No Errors)
 
Power Supply:
1. Special PSU Tester (No Errors, All voltage OK)
2. Normal Tester (No Errors, All Voltage OK)
3. S&M (No Errors)
 
My System:
Proccesor: Intel Core 2 Quad Q8300 2,5GHZ Lapped (Stock Never OC)
Mother: Asus Striker II Extreme 1402 Bios. (Updated)
RAM: 4GB DDR3 1333MHZ 9-9-9-24 Hynix (Single Slot)
Video: EVGA GTX 460 SuperCloked External Exhaust 1GB GDDR5 (Bios, Drivers Updated) 
HDD: Samsung Spintpoint F3 1,5TB 5400RPM Sata 2.
Audio: SupremeFX II
PSU: Cooler Master 550W
Case: Thermaltake V4 Black Edition with 5 120mm Fans/Led.
 
everytime i want play my PC is freezing bcus my GPU memory usage up. 
 
My gpu is already dying? or i can repair it? 
 
my GPU is cleaned with air. can i try to clean with contact cleaner?? 
 
 

 
Glad you were able to help find, and decrease the problems substantially.