I am finished slipstreaming 'Service Pack 2 RC1 Build 2096' with the original WinXP and everything went off smoothly. I think it is safe to presume that SP2 includes SP1 and therefore slipstreaming with original WinXP should be fine. Atleast in the case of MS Office service packs, this is always the case. If this is not correct in this case then someone please correct me.