Hello Optiplex GX110 (XP Pro) HD/BIOS problem I temporarily replaced the 10GB HD (Quantum Fireball) with another HD I wanted to test (it turned out to be faulty) - when I reconnected this original 10GB HD it is not being recognised by the BIOS - error message is 'Primary hard disc drive 0 not found' I checked that the HD controller is enabled in the BIOS and the HD select is set to 'Auto'. I upgraded the BIOS from AO3 to AO9. I reset the NVRAM but could not find how to reset/delete the 'Error log' (maybe this is stored on the HD?) I ran the Dell diagnostic floppies, but they also do not see the HD. I tried another identical HD with the same results - not recognised. I removed/tested/replaced the motherboard battery. Any suggestions please - is there something else I need to reset to get the HD to be recognised ? Thanks for your help Chris