Welcome to the Wonderful World of Windows 7 64-bit, where the Motto is"We'll Driver You to Drink!"
Joking aside, I'm also slogging through the migration from XP Pro to a new Win7/64 machine. Although I can offer you no firsthand advice installing the EOS utils (I'm still trying to get my *%#*!! scanner drivers updated), if I were in your situation I'd first manually create a restore point (S.O.P. before installing anything on Win7/64), then try installing the EOS software as Administrator. If that failed (and I'd be prepared for it to fail, or at minimum to create a conflict with another driver), I'd try to contact Canon for updated software (expecting there'd be none), while simultaneously Googling to see who else was having the same issue. And of course, posting here on LL.
Good luck. Those of us who are about to follow in your blood-soaked footsteps salute you.
I will keep on trying. Concerning your scanner, I had the problem of Epson not writing a Win7 driver for the model. I found a publisher named Hamrick, with a product called VueScan. The publisher has written drivers for many "legacy" scanners and other peripherals that way surpass the scanner manufacturer's drivers.
While I don't have the link handy, Google Hamrick and/or VueScan and I'm sure you'll find it.