This could be hardware or software. Try this:
Right click on "My Computer".
Click on Properties
Then Device Manager.
Click on the + next to CDRom.
Is your CDRom drive listed?
If it is, click on it then click on Properties.
Click on Settings.
If the box next to DMA has a check mark in it, click on the box to remove the check mark. Click OK then reboot the computer.
If its not listed then it could be hardware related in which case you'll need to open the box and check connections, etc.