I see a lot of posts about that but installing Windows 7 is far from easy enough. I can't see your plan so let's hear it.
Bob
I am trying to install this software so I can use the scroll button in certain programs. Even picture preview won't scroll without the software. The mouse works fine, has done for 3 years with this software but I bought a new SSD about a month ago and reinstalled the OS, and since then the software comes up with Error Code 1603. I try to reinstall and get a message that I must at least have Windows 7 installed. I have Windows 7 SP1 since it was released.
I'm lost here, help appreciated.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic