Error detected on device \Device\CdRom1 during a paging operation

Recently began getting this message at start up. Splash scrren comes up and then black screen with flashing cursor and it takes about 3-5 min to start loading OS. I updated BIOS & drivers and nothing changed. I searched back in event viewer and found the date it began to happen so I did a system restore 2 days prior to that date, still no change. I also did go into set up to verify the boot sequence and all is correct.  it is listed as an Event 51, but I can't find anything on it that shows this issue.  I am now leaning towards a hardware failue, but I am not sure. Does anyone have an idea what the issue is?

435MT

Windows Vista Ultimate 64bit (service pack 2) I7-920,12GB DDR3,