Windows 7 64-bit works, is a PITA to install on a 1,1, you won't see early video out, but works fine - IF you manage to get it installed.
Boot Camp. Bad name. Don't use it generally. Drivers, yes and no as Apple support on 1,1 is abysmal. BCA: don't. Just pull all drives but one and install Windows.
Downloading Apple drivers for Windows use to be on the OS X 10.6 DVD now they are download in BCA or directly. Installing them there are workarounds as Apple wants to block x64 drivers on EFI 1.1 (and does not support).
Was Windows on 1,1 your original and main use and why you are asking or just another issue that came up?
Install Windows on a PC then quickly before it boots on the PC move the drive to your Mac, or just buy a i7 4xxx mobo and Intel cpu and you'll be miles ahead.
Yes I did run Windows 7 and 8 and 8.1 on 1,1, but left it for my own PC.
Windows Vista pre-SP1 64-bit was easy piece of cake. Then it started getting harder and had to use Imgburn to redo the ISO DVD.