some months ago I installed and ran CCleaner (was recommended by PCWorld). After that, I detected problems with both my DVD-ROM and CD-RW drive. The access is very slow (sometimes lasts more than 5 min. to get a listing of the folders and files in explorer) and I am not able to install any program from CD since then.
Somehow I think that something (in the registry?) was deleted. By the way: I used both drives quite seldom and maybe the program "decided" that I do not need them ...
If you've uninstalled any CD/DVD burning software that can cause an issue of being able to access your drives or even being able to use them at all. Anything that installs the Sonic Burning Engine and when uninstalled can cause issues as well - which isn't always an easy fix.
There's also the possibility of DMA being switched to PIO mode if read-errors were detected on a disc, here's an enabling DMA guide to check that DMA is activated on your CD/DVD drive.