Asus m2n68-am se2

did you check the memory modules against the QVL list

I Have checked now.
I am using ocz gaming memory which is on the list, they are 240 pin 2Gb x2 dimms 800mhz.

The only other thing that I have come across on the forums is that this board has problems with sata drives I only have a single hard drive which is a 1Tb but I am also using a sata dvd/cd writer this could be causing the problem if you go to microsoft they list this as a problem for all vista/7 operating systems not xp, seems a bit of a coincidence that I can only load XP? if you have any idea's please could you help.
Thanks for replying to my thread.