Again, what do you want to program? Programming languages are pretty universal and most packages will work on any operating system. Maybe older unsupported languages may need you to emulate an XP environment to work (which is something Vista can do).
I've only done Java and VB - both work great in Vista and 7.
I think C or C++ are good languages to start with.
It's not really more difficult to start with them; just doing more advanced things requires more knowledge.
Plus, C and C++ teach you more about how the machine operates.
And at the same time, most languages are made to be C-like; so it'll be easier to learn other languages.