By "virtual machine" I mean a software program that will actually simulate a second computer inside the first. In my case, this would be for running Windows inside Linux for certain games without having to dual-boot, since I wouldn't want to shut down my linux server programs, etc. What software is good for this? BTW, yes, I know this will be much slower than a dual-boot, but unless it's about 10x slower there's no problem. Thanks.