after reading your previous post and no getting anywhere i think you are better of reinstalling windows os system and see if that resolves the situation. Im presuming your using XP i hope you are. But before you do back up and save files to a externl drive in case you need them later.
or try this click here and dowmload the optimiser and use the defrag there. or better still buy a copy of pc advisor it comes with a disk and try gary utilities.