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?