Windows 7 has been very recently released for public, it is the most efficient and better OS released by Microsoft till date, I would say it is upgraded version of vista after removing many buggy things and make it more flexible and faster now. Many users like me would like to upgrade to windows 7 but how do they know whether there old hardware and software will work with windows 7 or not.
Windows 7 Upgrade Advisor is an official tool by microsoft itself which lets you find out how you can install and run windows 7 on your old computer or laptop, After installing when you run this tool this will run full scan of your computer which will take some good amount of time, so something else and let the compatibility check complete in background.
When it completes it will show you the issues you need to solve and will also tell you how to solve them, In my case it found 6 issues on my Vista home premium laptop which I need to sort out before going for windows 7 upgrade.
It will also tell you which of your currently installed programs are not compatible with windows 7, so that you can find out the compatible version of those programs.