Mulitiple Performance tests across 3 pc setups -

[TonyD]

I would think that the major limiting factor with your pc is the OS - try Win7 and I'm sure you'll find that it runs it a great deal better. Crysis 2 is not a good indicator as it uses DirectX 9, and therefore XP handles it OK.

Luthier has said elswhere (?) that most of the worst glitches are associated with DX9 - others using a GTX260 with Win7/Vista have not had these hassles. Oh, and you'll need more RAM, too.