That's the issue.
Many types of software were running under XP.. when vista came out.. almost no sound software or hardware liked it. win 7 offered some hope.
the super high end software like protools steeped up first followed by lesser, but still high end software like cubase sonar.. NI etc...
Many peopl are just now swapping out of XP systems.. looking at win8 systems as they are more compatible than vista/7.
heck.. some of the midi controllers i have ONLY had drivers thru XP. midisport JUST a couple months ago came out with a 7 driver!!!! and then people were using it under at.. and now they finally have an 8 driver out. Vista 64 was the most cruel. many usb devices would not detect correctly under it.. The heavier systems usually had vista 64, not 32 home. thus if you bought a bulldog pc.. it had vista64 and then caused problems. we had SOME luck with vista 32 home.. but those pcs at the time were usually low end.. celerons.. low configured. so not much improvement.. if ANY over a heavy xp system.
I've been in contact with a couple midi producers here in fl.. and am picking up NI komplete 9 as well as a newer ver of sonar and a roland module.. plus the pc by the end of this year. the komplete9 is a chunk o' change..