It's all distorted looking, this didn't happen on my old computer but is happening on my new one

Specs

ASUS A8N-SLI Premium

AMD 64 X2 4400+

2048mb Corsair XMS PC3200 Ram

2 XFX Geforce 7800 GTX cards in SLI

and I have a Samsung Syncmaster 997DF 19inch monitor, though I doubt that's the problem