On my Windows 2000, it's under Control Panel -> Admin Tools -> Event Viewer
I've attached two screencaps to show what you're looking for. The first one shows an error event associated with the "cdrom" device. Normally, whenever I do something dumb like insert a DVD upside down, Event Viewer will show a yellow caution indicator, but I guess something more serious happened on December 17, 2005. When I double-click on it, I see the second screencap.
Since "error 11" tells me nothing, I went to
and entered "11" in the Event ID box, and scrolled down to look for cdrom as source. I then clicked on the "comment and links" link and it reported, [b]As per Microsoft: "This problem is typically caused by a failing cable that connects the drive to the computer".[/b]
btw: I replaced the secondary channel ribbon cable a few weeks ago when I installed the new Plextor..
old one crapped out after 2 yrs..
Looks like eltranquil nailed it in far fewer words than I. If you see a lot of those errors in the event viewer and they seem to be dating from when you installed the new cable (80 connector?), I'd say there's a good chance you have your culprit. Even though it's new, you might want to try another one.