Minimum:
o OS: Windows 2000/XP/Vista
o Processor: 1.2 GHZ or Equivalent
o Memory: 512 MB RAM
o Graphics: 64 MB DX9 Compliant
o Hard Drive: 2 GB free hard drive space
o Sound: DX 8.1 Compatible Audio
Recommended:
o OS: Windows 2000/XP/Vista
o Processor: 2.4 GHZ or Equivalent
o Memory: 1 GB RAM
o Graphics: 128 MB DX9 Compliant with PS 2.0 support
o Hard Drive: 2 GB free hard drive space
o Sound: Eax Compatible
Yeah its not really a rig built for games, you have maybe enough to run just Killing Floor, but given that you need to run steam as well your lack of RAM is going to cause you alot of problems. Your processor isn't really ideal either, and again with steam in the mix I think you are going to have issues.
I'd say it might run, but I think your going to be pushing the envelope. I personally wouldn't hand on heart recommend it.