I know it says Cakewalk doesn't support anything but Windows 7 or Windows 8. My PC has Vista and I'd like to upgrade to X3 but I don't want to upgrade my PC to do it. Would X3 run on a Vista machine? Down the road I'll probably upgrade my PC but right now I can't

Disconnected : You want to talk to John .. who was in your position . and did the upgrade...OEM is about 100.00 and its night and day , there is no support for vista.sorry !

There's no official support for Vista. 

I'm John but I don't know what I can say. There are those that are running X3 on Vista. That I do know. I can't say if you will have their luck.  
 
I went from Vista to Windows 8 to be X2 compatible and I'm very glad I did. So I have been running Win 8 for about a year and it rocks. X3 loves it.
 
Then I got Windows 8 for less then $40.00 on two DVDs from MS. I don't know what to say if you have to pay full price as an update. One thing was I did a clean install onto a new 1 TB HD and I still can run Vista but I have no desire to do so.

Vista came out in Jan 2007.  Mainstream support for Vista ended in 4/2012.  Extended support ends in 2017.  Vista had issues... upgrade to Win 8 and move on.  U want the latest DAW but not the OS to go with it???