Using Disk Defragmenter in 98

I have a problem using the Disk Defragmenter in Windows 98. As soon as it gets to about 10% done, the scan restarts saying it detects a change in something and must restart. I tried disconnecting from the internet and closing all running programs however the problem still occurs. I looked for a way to scheduel a scan at system start up however I couldn't find anything. Anyone know how to get it to work?

 

Run it in safe mode. What is happening when you try to run it after a normal boot is that when windows does normal access to to the drive it interupts the defrag and it has to start over.