Thanks to all who advised on this matter.
Kam's suggestion of trying a text-mode install was a good start. Adding
the options noacpi, noapic and noapind helped.
At Renich's suggestion I did try the test version of FC7, but couldn't
see the cursor after I logged in.
I now have FC6 up and running, with 282 updated packages, and all is well.
Only minor problem is that when I boot from XP to FC6 or vice versa, I
have to re-sync the time, even though I have both set to obtain the time
from the time server.
Jim