I have just bought a secondhand pc,after cpu failure on my other,it's a amd1400 american trends motherboard sis730 i put my maxtor 40gig drive with operating system(xp) no problem but when i put 120gig wd caviar n it stops xp from booting up.i have tried numerous jumper configs to no avail,been to american megatrends site for bios upgrade but they seem to want to sell you it,and im not sure if it is a bios prob as 40 gig drive is ok,anyone have any ideas?