-run some registry cleaner / fix software if you are on Windows once in a while.
-buy a cd optical cleaner and run it for few minutes in the computer's dvd/cd drive
-create a startup floppy diskette (if you have any) or bootable CD with DOS in it with some basic utilities in it like partitioning formatting hard disk and recovery/restore . DOS commands understanding is necessary.
-run printer alignment program and nozzle/cartridge cleaning every once in awhile