Re:sonar x1 system requirements
I wouldn't say XP is "recommended". I would say X1 will run on it with the sp3 update.
X1 is really aimed at Vista/Win 7. The reason that XP sp2 is not on the list could be because CW didn't test it on that that.
Too many things are in Vista/Win 7 that X1 can take advantage of that are not apart of XP.