I read the PDF also. However, I was hoping the October 2001 BIOS upgrade helped with the XP. I was thinking might have to unlock the 266fsb XP or Tbird to increase the multiplier for operating at 200mhz fsb to get rated speed or even OC; i.e. 12.5x with the XP. I read that this board, with KT133, does not like over 110mhz fsb; i.e. 133mhz fsb. I was also hoping, as an another alternative, the locked 1.4ghz Tbird @ 200mhz fsb would work even though the dip switch mulitpliers only go to 12.5x. I read somewhere that the locked 1.3ghz actually runs at 12.5x but with an automatically increased fsb to 104mhz. To run 1.4ghz with 12.5x multiplier would take 112mhz fsb. Why do this? I am looking at replacing a Duron 600@950 with the 1.4ghz Tbird or XP until I get a better board. Any experience or info would be appreciated.