A friend of mine has been working some time under an XP-SP1 environment without a hitch. One day, while opening an e-mail, the pc crashed. It would not boot anymore. The BIOS would recognize neither the disks nor the two optical disks. The 2 IDE disks were on primary connector and the opticals on secondary. I switched the cables around, I switched connectors. At one point in time, the two optical disks were rwcognized but not the ide disks. I tested the system disk alone with each cable and each ide connector in succession. No dice. Not recognized. I then connected the system disk to a second similar pc (it has the same model motherboard) as slave. It was recognized on the 2nd pc. I then launched an antivirus on it but I didn't go all the way through (too lengthy). I was also successful in booting the system disk of the 1st pc on the second pc. I then went back to the first pc and connected the system disk all by itself. It was recognized and I managed to boot successfully after having gone through safe mode first. When I connected the second ide disk as slave alongside it, it didn't recognize any one of them! When I disconnected the slave, the system disk worked okay. It's not a jumper problem, I've checked that closely. They are Western Digital disks and jumper setups are clearly shown. Another interesting item: when I succeeded in booting with the system disk alone on the 2nd pc, at some point in time, the system froze. This could be linked to the mouse. My friend bought a new one and connected it with an improper driver. I didn't have a chance to go any further. Would a virus be responsible for the BIOS not recognizing the two disks connected at the same time?

A defective drive 'can' cause the controller to fail and not detect the other drive. Do yourself a favor BACKUP!

I doubt a virus is the cause. With most WD drives, one by itself on the cable would be a 'single' and there'd be no jumper. You'd only jumper it as master if there was a slave connected also. Try connecting the slave as a single and see if the bios recognizes it then.

I'll do that and also connect the slave to the 2nd pc and see what happens.

The second disk turned out to be defective, unreadable on either pc. Now, a new problem appeared. The first pc doesn't boot at all with the operational standalone system disk. As soon as I power on, I get an unending series of 3 long beeps with a slight interruption after every threesome from the AMI BIOS. With all the fiddling around on that pc, the BIOS probably got corrupted somehow or other. What’s surprising is that I get no message on the display. It’s powered on, but it’s not used at all. So I switched graphic cards between the two pc’s, but that didn’t help. I even switched the power supply between the two pc’s. It’s not defective. In the AMI beep code inventory, 3 SHORT beeps are used to report defective RAM. I get LONG ones. Anyhow, I checked the RAM’s by switching them between the pc’s, but that didn’t improve things either. I find no interpretation for the long beeps. Is there anything I can try before resetting the CMOS?

Resetting the cmos is no big deal. I doubt it will fix the beeping problem but there's no reason you should avoid doing it. You may want to check the motherboard manual for that particular beep sequence. It doesn't show on the beep lists I checked either but ASUS may have made some modifications.

I’m not sure I can locate the CLRTC1 pins on this MB. There is no documentation available. If I just remove the battery for a few seconds, is that enough? I can use the BIOS parameters of the sister pc (pc1 in my description earlier) to reinstate the pc2 BIOS settings appropriately.