You're using the wrong workaround
This fix is designed for people who can't see their drives in My Computer. I'm afraid your drives not reading discs is another entirely different problem, so please don't use the instructions I listed as a fix.
Unfortunately the problem you're experiencing could be caused by any number of issues. I recommend you do a search of the forums and see if anybody is having the same problem as you. If you can't find anything, start a new thread listing you're problem in as much detail as possible including when it stopped working and what you did just before it stopped working. The more information you give, the more likely it is that someone will be able to correctly diagnose your problem and recommend an appropriate fix.
Bare in mind though that its possible the drive is broken and will require replacement, but it's better (and cheaper) to exhaust all other options before going out and buying a new drive.