Unfortunately getting it to work in Vista may be easier than in Win 7, and if you are using Win 7 64 bit, harder yet. This model never had any drivers developed past Win XP, 32 bit. Getting those to work in Vista 32 bit may not be hard to do, but Win 7, and especially Win 7 64 bit is another thing altogether.
If you are running Win 7 Ultimate, you can try to install the XP drivers in XP compatibility mode, and that may work, although as some have found, XP compatibility mode is by no means all-inclusive.
Scanners are one of the hardware areas hardest his by Win 7. Some of Canon's scanners are downright un-useable. Not to point the fickle finger of blame, but it really is the hardware companies that either update their drivers, or fail to do so. Of course the 1200UB plus is pretty long in the tooth, hardware wise as it was developed back in the Win 98SE days...but it was a very decent scanner...