Personally, I recommend that you not use jv16 on x64 Vista or XP until such time as it becomes fully compatible with x64 systems...especially if you are not an experienced computer user. PT 2009 build 531 will "partially" work; however, the possibility of registry mistakes is pretty high even with that build.
jv16 (Jouni) is working on a new build (yet to be released for testing) that is supposed to make PT 2009 x64 fully compatible. It is supposed to be released for testing very soon and will not be released as an official build release until testing is completed.
JMO...