It has been widely asked question lately, does Skype support Windows Vista or not?
Well to start with the official answer, then it is that Skype does not currently support Windows Vista as of version 3.2.
On the other hand in real life Skype works on Windows Vista pretty ok. It may have problems with audio and video calls on some configurations, mainly due to not mature enough drivers.
You are welcomed to try Skype on Windows Vista, but when doing it first please make sure that you have installed absolutely latest audio, video drivers and updated Windows Vista.
If you encounter problems when using Skype, then please report it to us, so we can solve those issues for you.