I am using Windows 98SE, Office 2000, 192MG RAM 15GB harddrive. I do a DiskCleanUp, Standard ScanDisk, then try to run the Defrag. (I have also twice now run a Thorough Scan to see if that would solve the problem...no go. It gets to about 4% stops and gives me the error DEFRAG004. It can take up to four attempts between ScanDisk and Defrag before I can actually get the Defrag program to work. This has been happening for about 6 weeks and is really annoying. Any assistance would be greatly appreciated....thankyou.