My dad had to use VUESCAN as there was no support for Windows 7 64-bit for his scanner:
http://www.hamrick.com/
It works quite well and is the ONLY good solution if your scanner software doesn't work.
So:
1) Windows 7 64-bit drivers? (If no, NEXT)
2) Windows Vista 64-bit drivers? (If no or don't work, NEXT)
3) VUESCAN (use 64-bit version)