Had a quick look through the drivers list here :
http://esupport.sony.com/US/perl/mo...te_id=1®ion_id=1&tab=download#/downloadTab
It seems most of the drivers listed should have no issues running on Xp.
Out of curiosity why are you downgrading? performance issues?
How did you solve your problem? What was the fix? Curious to know....Sorta, plus I heard xp is way better and also I solved my problem thx