Is your computer connected to the internet so that Windows 7 can download the appropriate drivers for the mouse?
Also, Microsoft does have an official Windows 7 Support Forum located here http://social.technet.microsoft.com/Forums/en-US/category/w7itpro/
. It is supported by product specialists as well as engineers and support teams. You may want to check the threads available there for additional assistance and feedback.
Microsoft Windows Client Team