In what settings can my pc run these games?

Witcher 2, Battlefield 3, and Dishonored.

My specs are:

Intel quadcore processor 2.5 Ghz

Geforece 9800gt 512mb

4g of ram

Windows Vista (sp1)

If I had to make an educated guess than I would say medium settings @720p

9800GT is old but 720p isn't that demanding + medium settings isn't super demanding (on most games its only 2 out of 4 since it usually goes low, medium, high, very high).

Probably medium? I think at high/ultra you're going to get unplayable frame rates.

i don't think it can play high... unless you modify the games to have lower settings.

720p: Witcher low, BF3 mid (with FXAA and AF probably), Dishonoured high

1080p: Witcher will be basically unplayable, BF3 might be ok on low, Dishonoured at least medium

Thanks guys