DVD and CD optical drives simulteniously dead

I hope I am in right forum, if not, please direct me.
My system: OS WinXp with SP2, two Maxtor 250Gb HDD on one IDE channel and "Plextor716A" DVD/RW as a master and "HL-DT-ST CD-RW GCE-8160B" CD burner as a slave on the second channel.
This set up had worked well for a couple of years until this afternoon, when both DVD drive as a drive G:\ and CD drive as a drive K:\ disapeared from windows explorer; NERO does not see them either, neither does the Plextor driver upgrade software; it claims "NO DRIVE". Inserting CD or DVD doesn't get recognised either.
NO new hardware or software installed, only the periodic Windows updates.
Both optical drives have power and WILL open/close.
I have tried cold reboot, removing and installing ribbon cable; un-installing both in device manager and installing; same; Both devices show a yellow triangle with a exclamation mark in the device manager.
BIOS seems to recognize both.
Is it posssible that a one side of the controller would be gone/dead? (ASUS motherboard PCI/I-P54TP4 with on-board controller) If it is dead, could controller card be added to gain second channel?
I didn't try swapping the HDD with optical drives yet.
Please, help

try to delete the ide controller from device manager and then restart

I ended up contacting Microsoft for help; they found out the problem was caused by recently installed freeware Burn4free (used to burnd DVD from avi files).
This software had never worked; I had un-instal it but it had messed up the windows registry so both optical drives became unvisible (un-instaling it didn't fix the problem).
Both drives now work fine.
thx