Thanks again everyone. I received an e-mail from him today and this is what it said:

After I "played around" some more with the DOS commands, I again
tried to do a "registry restore". (I had tried this initially, but it wouldn't
recognize the command.) I finally was able to find the command under
C:\Windows\Command\scanreg.exe . Then when I did the "scanreg /restore"
command, it gave me a choice of 4 dates to select. I chose the earliest,
which was 1/26/05. Then, when it rebooted, Windows 98 worked normally
with the Taskbar & Icons showing.
So far so good.

He's pretty good with computers so I was hoping that he'd eventually work it out on his own. I also copied the info about starting his computer in safety mode for windows 98 for future reference.