Why does a a printer with Windows Vista drivers not work with Windows 7.

Microsoft has it own ever changing thing. The Permission levels are given vague names. That have various limitations. You may get the correct results by playing with various settings, or not.

I see and have read of constant issues with permission levels for a long time. Microsoft's wishy washness causes a lot of software ( including some of mine) to do things that will not work at all permission levels. And that will not work on future OSes. it is made worse by messages that do not tell you that it is a permission problem.