The "official" minimum specs for .kkrieger: chapter 1 beta are:

A 1.5GHz pentium 3 / athlon or faster.

512MB of RAM.

a GeForce4Ti (or higher) or ATI Radeon8500 (or higher) graphics card supporting pixel shaders 1.3, preferably with 128MB or more of VRAM.

some kind of sound hardware.

DirectX 9.0b.

however, there's bad news: due to an unnoticed build error in the actual released version of .kkrieger, there are severe shadow bugs on Geforce4 and Radeon8500/9000 cards. the game should be playable, but everything will be way to dark.

the full list of known bugs (which will of course be fixed in the final version) is: