Okay, I bought a Geforce 8400 GS for a old gaming pc, anyway after a week of use, I got blue thick vertical lines on me screen, its nothing to do with the drivers, because the lines show in the BIOS. I have done the "baking" trick where you put your GFX card in the oven and cook it for 8 minutes and set the temperature for 385 F. Anyway it fixed it for about 13 hours and then it started again. I also removed the fan after all of that happend, and I'm hoping a new fan will fix it. -Sam 
My Computer
At a glance
Windows 7 Home Premium 64-Bitcore 2 duo e8400G.SKILL Ripjaws X Series 4GBEVGA Nvidia Geforce 8400 GS
- Computer type
- PC/Desktop
- OS
- Windows 7 Home Premium 64-Bit
- CPU
- core 2 duo e8400
- Motherboard
- GIGABYTE GA-G41MT-S2PT
- Memory
- G.SKILL Ripjaws X Series 4GB
- Graphics Card(s)
- EVGA Nvidia Geforce 8400 GS
- PSU
- Thermaltake SMART Series SP-550PCBUS 550W ATX