Defrag of Exchange running for 24hours

We are running Exchange 2000 std. We reached the 16gb limit. After modifying the registry to allow exchange to run, I had all 70 users create PSTs and archive all email up to 6 months ago. I started my defrag last night at 5pm and it is still at 40% tonight 10pm. 29 hours later. does it usually take this long??? Please help