Dunno about WinXP, but my Santa Cruz runs beautifully under Win2k with my Altec Lansing ACS56. Absolutely no problems at all and the sound is sensational. The current Win2k drivers are superb. Although I never had any problems with my old SBLive X-Gamer (4:1 version) under either Win98/Win2k, I can say that this card is distinctly better in almost all areas. Not to say that my old reliable X-Gamer was bad, just that the SC is better. Had the Herc GTXP for awhile too, but it was buggy as hell with 4 speakers so I took it back.