I just finished now configuring my laptop to function as follows:
My laptop is a toshiba Satellite M45 Series. The host operating system is Windows XP + SP2.
I have created a Virtual PC with the guest operating system as Windows 2003 Standard Server and installed on it most of the development tools I use, including:
Visual Studio 2003 + Visual Studio 2005 + MS SqlServer 2000 + FireWorks MX 2004 + IE 6.0 + FireFox 1.0 + MS Front Page 2003
Then I backed-up the new VPC which is around 7GB to an external HardDisk.
I will now format my host machine and have a clean installation of WinXP SP2.
This way, whatever happened to my guest machine, the basic tools which usually takes like 6 or 7 hours to be installed will be preserved now.
You can also, create a VPC with any windows installation and keep that VPC as a Base HardDisk, then I can create other VPCs out of that Base HardDisk by inheriting from the base one.
Hope this post helps you out.