From what i've read, Vista is the interem release of 7 so most of the mechanics are pretty similar. The only real difference will be security, some loading items, resource management, and the desktop enviernment. I have no idea on the OS byte-types but if its an "upgraded" of vista to 7, then it should work.
I use Windows 7, heRO works perfect for me. There are very rare problems where it doesn't catch any input you put into it, but that's solved by an alt-tab and an alt-tab back.