What do you do?
As long as you haven’t removed the program or deleted your hard drive – there are several options, one being hacking your registry as in Rich’s recent post: Crack Windows Password [How To]. Here’s another solution.
Using a freeware tool from Abelssoft called MyKeyFinder you can search through Windows, recovering almost any serial number ever installed on your current system. Even Microsoft Serials can easily be recovered using this tool.
What I love a bout MyKeyFinder (apart from the obvious) is that it’s totally free and that it has several export options, making it very easy to save your retrieved serials in a safe place.