Ah, I see.
FYI there is a fix for the "missing" CD rom drive you encountered.
Was the recovery you ran off of your CD's or off of the recovery partition?
Running a diagnostics would consist of running a hard drive test & memory test for the basic stuff.
I would recommend Hitachi's Drive Fitness Test and also MemTest 86+ for Hard Drive testing & Memory testing. You would need to google these and download the .ISO, burn the image to a disc, and then boot off of the disc's. If you would like assistance with this we can help.
Thanks