missing texture in CFS3 and FS2002

I have Combat Flight Simulator 3 and FS2002 loaded, both worked well until
recently. CFS3 now does not show aircraft or buildings in the opening
sequence,only white.The pilot is rendered about 95% and the grass etc is
fine. Also no cockpit canopy framework detail is shown, again only white.
FS2002 also started to behave badly at the same time. I get the control panel
but the scenery is extremely poor and does not really refresh properly, just
a moving blur.
I do have other non MS aviation sims and these continue to work perfectly.
These problems started some weeks after I loaded SP2, but they did work for
a while.
I have the latest driver for my Leadtek Winfast Nvidia Geforce2 GTS/GeForce2
Pro video card. AMD Athlon 1.4, 512Mb RAM.