Can someone please assist me with a solution for the
locking up of a computer when executing the Disk Defrag
utility on Windows 98?

When you execute the utility, the box pops up like the
utility is starting to run, but all activity ceases from
that point. It is necessary to execute a hard boot to
recover.

(This is for my mother-in-law's computer... I will be in
good graces if I can come up with a fix on this one!)

Thanks.

an app is running and causing the defrag utility to
reset. also make sure that you have disabled any
screensavers.
Not an expert but hope this helps

It might be that there is a "bad sector" on the hard disk
which may be stopping it, OR there may be a virus.

Run your virus protection software, if you have one, to
see if anything appears.

Even if you don't, run Scandisk, it might pick up and
repair any bad sectors.

Hope this helps.