If you choose the right hardware, you can run Vista very well....

Keep in mind to install from a fresh created Vista CD containing all upgrades.

Next to that don't install Vista 64 bit when using vst's and such, many vst's are still only 32 bit. Many of htose and other musical apps refuse to work under 64 bit. As they are programmed for 32 bit and their programmers refuse to update them to 64 bit.

Next to that....... i'd stay away from both Windows and Apple stuff..... I'd go with Linux as its free, by supporting Linux and the free BSD community people will finally be free to have their OS as they want it to be.... When people start using Linux more and more, more and more software will be ported to Linux.