comctl32.dll file can’t start

I am working on a user’s computer that gives me this message when I get ready to log on to the network. The machine run win ’98. When I log in, I get the message “access to the logon server denied.” If I try to bypass the login, it just pops backup. I got a boot disk and ran Scandisk in DOS mode. There were several bad sectors on the disk which were repaired, but there is one error with a long filename that could not be repaired. The message suggests that I run Scandisk in Windows mode.Unfortunately, i can’t get there. What can I do short of starting over from scratch(cleaning and re-installing Win ’98)to fix this problem.