Norton AntiVirus 5.xx quits at 97%

I have a WIN95 OSR2 workstation that NAV (5.xx) locks up at 97% of scanning for viruses. The user claims that this started after our IT department installed Outlook. Subsequent uninstalls and reinstalls of Norton AntiVirus provide the same results (we even tried NAV 2000, same problem). If we turn on scanning of program files only,it seems to work. Since by contract we are to provide Virus free software, this needs to work for all files. Symantec has been useless in helping solve this. Thanks in advance!