I modded out an old AT case to take ATX gear to use some old hardware I had. The hardware wasn't working, and so I used different hardware I know to work well. I took an Elite mainboard (Socket A - k7s5a) and an AMD Athlon which is supposedly a 1.7, but rates in bios as 1.5 Ghz and shows as an athlon 1800 running at 266MHz, which is the correct bus speed for it. I used a 256 DDR 266MHz stick of ram out of my own and best rig, which works perfectly. The HDD came from the computer I 'm trying to 'upgrade', as did a CDRW and DVD ROM. Also from this old Gateway machine is a miniATX powersupply, which should be perfectly sufficient for the little work I'm asking of it. In the PCI slots is also a NIC and a VGA card. On booting this 'upgraded' machine, as was half expected, I got a reboot loop while WinXP had a fit dealing with it's new home. I used the recovery console chkdsk/r, and then repaired winXP from the installation CD. Rebooted the machine, and Windows XP loaded up as expected. Up and to this point, there's been no hint of a problem. However, if moving the mouse a lot or are doing anything when windows is still loading the desktop, the system crashes - a proper crash where everything freezes and the capslock light won't light up when you press the key. It just stays in this state untill you turn off and reboot. Waiting for it to boot, and then opening My Computer, and doubleclicking the mainboard installation CD also gives the same issue. A solid crash/freeze as soon as you try to move the mouse. I really have no idea at all why the thing should be freezing like this. This is turning out to be the longest it's ever taken to upgrade a machine!!! please help!