I have recived a code 41 error on my pc.

Clarifications

Some CD/DVD drives are not compatible with some HDDs - even some HDDs are not compatible with other HDDs.

Try the CD/DVD as a single drive on the IDE cable, and make sure the jumpers are configured correctly. If you added the drive onto an existing IDE cable as a second drive, make sure the CD is "Slave" and the HDD is "Master" and not "Single drive"

(First-guess, given the minimal details in the question...)

http://support.microsoft.com/kb/310123

You can see there for additional ideas.

You may also need to delete the upper & lower filters registry keys:
http://pcsupport.about.com/od/driverssupport/ht/upperfilters-lowerfilters.htm