Won’t Defrag HDD

Want to defrag a 10GB maxtor HDD. Win98 won’t do it. Partition error message?. HDD Partitioned with 1 active primary and 1 extended. 5/5GB with 40% free on both drives. Has ATAPI Zip-drive as well. All third party and behind scene software shut-down. Lots of RAM(Screensavers, Norton, etc.) What’s the obvious glitch? Many thanks in advance.