Error: CD/DVD drive not ready message when trying to read from the disc.
The only thing that will cause this is something in the Registry got messed up, so to fix this Open Hoster, click on the Tools Menu\CD DVD Default drives.
Now when you drives show up, click the Down arrow beside the drive showing on the line, then click it below that box again, rather its the same drive name or not.
Once you do this, click ok, then close out of Hoster completely. Now reopen Hoster and it should now work.