Are you scanning film or photos?
If photos, just about any flatbed scanner is fine.
Anything made recently should support W7, as said Canon make pretty decent flatbeds.
Check the specs on their website to be sure or simply ask your local shop.
If you are scanning film in large quantities you will need a dedicated film scanner. Nikon make good scanners. If its just the occasional roll, you are far better off getting a shop to use their $50,000 drum scanner.