One product which is available from Microsoft is Microsoft Virtual Server.Its a good product to test other Operating systems without disturbing the current configuration.You can load
Linux, other flavors of Windows on this virtual machine.The Virtual server can be accessed through browser.IIS is essential component for installation for this virtual server.
If you are going to test 32 bit OS then you have to load it on a 32 bit platform only and this is same for 64 bit platform also.

You can download Microsoft Virtual Server from this location.

Other product which is available for virtualization is VMware.