You could try the Workstation family of VMWare. Besides the full Workstation product which is a paid piece of software they offer the VMWare Player which includes the basic functionality of the Workstation version. If you don't need advanced features like making snapshots of your virtual machines this might be an option to try. And itīs free. I use version 3.0 to run multiple Linux boxes (both 32 bit and 64 bit) on a 32 bit Windows 7 host.