Have you tried defragmenting your drive?? I recommend doing this once every month or two.

Is the computer just running slow in general?? If so you may need to upgrade your RAM or Processor.

Don't format your hard drive, only do that as a last resort. If your computer is running slow or laggy then formatting is going to do absolutely nothing, lol.

EDIT: When my CD-ROM wouldn't open, my motor just broke. That, and the power cord wasn't plugged into it all the way! Check and make sure EVERYTHING is plugged in snugly (turn off your comp before doing this, obviously lol)