corrupt CAB file

I'm trying to reinstall Win98 on my roomate's P66.
A long time ago I copied the necessary files to a
separate partition, so everything is supposed to be
there. However, during setup I get the following:
'Setup has detected a corrupt Setup (.CAB) file.'
Argghhhh....!!!

Of course, in its infinite wisdom, setup doesn't tell
which file is bad, but it throws this error when the
meter (file copy progress) is at 22%. Can anyone
tell me from this which CAB is corrupted?
Alternatively, how can I find out which CAB is
corrupted? Is there an info somewhere on C: that
indicative of progress?

Said PC have a good floppy so transferring a CAB
or two shouldn't be a big issue. However, not only
it has an old SCSI HA, the SCSI CD-RW in there
wasn't working very well in Win98 with the drivers
installed, so copying the whole CD anew isn't easy
to do at this moment.

TIA