If you're interested in setting up a test environment for SQL Server 2005 Express or any other software, you might want to check out some of the cool (and totally free) virtualization products from Microsoft and VMware.

You can create a virtual machine (VM) on your desktop by downloading Microsoft Virtual PC 2004 at:
&nbsp &nbsp &nbsphttp://www.microsoft.com/windows/virtualpc/downloads/sp1.mspx

You can create a VM on a Windows server by downloading Microsoft Virtual Server 2005 Release 2 (R2) at:
&nbsp &nbsp &nbsphttp://www.microsoft.com/windowsserversystem/virtualserver/software/default.mspx

You can also use VMware Virtual Server to create a VM on a Windows server. You can download the application at:
&nbsp &nbsp &nbsphttp://www.vmware.com/download/server/