PC Optical drive driver/registry problem. Help!

I've had a DVD reader and a separate DVD writer in my PC.
A week or so ago I noticed that a disc I tried to use didn't work in either drive.
I didn't have much time and forgot about it.

I just installed a new BluRay writer (in place of the DVD writer) today and that didn't work either.
Every time I restart the computer, I get 'install driver failed'.
It's a LG BH10LS30 and is supposed to be Win 7 compatible.

I've tried via device manager to uninstall/update drivers.
Didn't work.
I ran Microsoft's Mr Fixit.
Didn't work.
I did get an error message 'Windows cannot start this hardware device because its configuration information (in the registry) is incomplete or damaged'

Apparently there's some sort of driver conflict going on (I think I read that somewhere) and I can't get either drive to work.

Help!