My Friend Pankaj has posted a Good Information for those who want to upgrade to Windows Vista.
Windows Vista Hardware Assessment
The Windows Vista Hardware Assessment solution accelerator is an inventory,
assessment, and reporting tool that will find and determine if computers on a
network are ready to run the Windows Vista operating system.
Windows Vista Upgrade Advisor 1.0
Windows Vista Upgrade Advisor is designed to help Windows XP users identify whether their PCs are ready for an upgrade to Windows Vista, which edition of Windows Vista meets their needs, and which features of Windows Vista will be able to run on their PCs