Dell did ship these with Phenom II-X4 CPUs, so most of the Socket S1-G4 CPUs should work. Stick to models with identical or similar power requirements - installing a CPU that requires more power than the original, is an invitation to system instability.

please help me some? i just bought a NEW alienware X51 yesterday and it works fine.. but today i accidently format my alienware without backup.. so is there any way that someone can give me the factory backup? how do i restore my alienware like it 1st came? i install everything on the CD but

2) I am asking question 1 because this machine had a virus... which upon rebooting to complete removal the machine would show the windows moths flying around and coming together, than a fast flash of a blue screen with white letters, then it would begin to boot again... in an endless loop.