Yeah I've since found out from this article http://www.msfn.org/board/index.php?act=po...=81&t=88083 OK here is what Microsoft says: The BIOSes on these motherboards is incorrectly reporting CHS Values (240 heads). The problem has to do with the algorithm used to calculate CHS settings and the difference in policy between drive partitioning between Diskpart 1.5 (which aligns partitions on cylinder boundaries) and Diskpart 2.0 (which aligns them on 1MB boundaries). When partition sector comes along, that has been created with diskpart 2.0, Windows XP tries to change the values for the logical end of partition and translate them into CHS values, which fails therefore booting the operating system also fails. Your options are: -An updated BIOS from the motherboard vendor to correct the invalid CHS values. Many vendors have already corrected this and that is why some motherboards fail and others do not. *This is the ideal and correct solution* -A software change, if created, would be to Windows XP setup. This would then require you to update all of your Windows XP configuration sets to include the hotfix. -Use the older version of WinPE when installing XP. I am guessing the same applies for windows 2003. You mentioned you used Gdisk to fix the problem. What commandline did you use? Cheers