When compact discs first came out, some PR genius pronounced the new digital medium so reliable that it could "practically" be played through peanut butter. That, as anyone who has been a little careless with a disc knows, is a bit of an overstatement.

These days, consumers are finding their discs pocked and scratched to the point that they're as unplayable as their scratched LPs used to be. Fortunately, a few companies have been offering CD fixes for years, and the business is now starting to generate interest -- and profit -- as the market expands to include CD-ROM and DVD.

The first line of defense is always a good, gentle, cleaning. Compact discs, it turns out, are much like the records they replaced: Keep them clean and they'll keep you happy for a long time. You don't need to buy some fancy cleaning solution, either; mild window cleaner and a soft, lint-free cloth (what you'd use to clean eyeglasses) will do. Remember to rub directly outward from the center of the disc, not in circles.

If that fails, then you can escalate to a CD repair bundle. We tested Maxell's CD/CD-ROM/DVD Scratch Repair Kit. For about $9, you get a "cleaner, polish and sealer," scratch-removing liquid paste, plus cleaning wipes. The kit came through on a moderately scratched disc, restoring it to playability within 10 minutes. We also tried a bottle of liquid auto wax, which worked just as well for only $2.

For badly scratched discs, it might be better to call in the professionals. Compact Disc Repairman, Inc. markets commercial machines that refinish CDs, much like a carpenter sands and refinishes scratched wood. Two companies in this area offer the service at present, DNA Telecom/ECRT, Inc. in Sterling (888/236-2835) and Video Game Exchange in Bowie (301/352-9395); the CD Repairman Web site also offers mail-in service.

We took three compact discs to Sterling in various states of destruction. The cleaning, which cost $11 and took less than 30 minutes for all three discs, was mostly successful. Two discs played without incident and a third, a copy of A Charlie Brown Christmas that had been thoroughly stomped by a co-worker's 3-year-old grandson, went from unplayable to merely having a few skips.

The technician said he had been able to salvage most of the discs he had seen in the few months he had been restoring them. Discs with scratches, gouges, even one with shampoo. But never one with peanut butter.