Computer stopped recognizing cd dvd drives

[artp]

This is my first post on this forum. I have a Dell Deminsion 8400 which I recently upgraded to 4 GB memory. The computer is running fine, but it now does not recognized the cd dvd drives. On boot up I get an message "not reading drives 4 and 5" I can press F1 to bypass and the computer boots up. I tried upgrading to latest bios, but that did not help. I am running WindowsXp home edition and I have the latest updates installed. Can someone please help me on this? Thanks.

 

[CCT]

The 'Standard' first thing to try is outlined here:

http://support.microsoft.com/default.aspx/kb/314060


Merry Christmas (I am overposting)