In Response to Jim and Ed both:

Thanks, and yes, I have made some changes that I thought were
innocuous. First, I do have the machines networked, using W95/98
networking right off the CDs. BNC Ethernet, thin and slow but
enough for what I need, via LinkSys cards, NE2000 compatible.
Second, on the W98 machine I did put in an extra 64Mb RAM, of
the same type that came with the original machine. The rest of
it is as delivered by the OEM. The W98 PC is the first one I
tried with VFP. In my specs this morning I typo'ed the BIOS
ID string. The BIOS date is 6/25/98, nor 6/25/63 as I typed.
And although I've only had the machine since November, I have
not seen any other software create this kind of behavior.

The older machine is running W95, and it too scrambled the FAT,
just when I tried to add a report to a project. Blue screen,
the whole bit. I can see clues now when it's getting ready to blow.
I clicked the Documents Tab in project manager today and it showed
me the Data graphic. I saved what I had open right away, quit VFP
and rebooted. Scandisk showed no errors and I worked again for a
while. The same thing happened later and I took the same steps.
I can claim that I avoided getting the drive scrambled but by the
same logic I was also keeping the elephants away.

So while I'm leery of reports, I will have to deal with them this
week in some way. Probably by packing them into the setup files
and not putting them in the project itself.

And I will look into the motherboard issues as Ed pointed out.

Danke ..

-- Bob