windows protection error on w98 startup

When booting a win95 machine I get a “Windows Protection Error”
Press any key to continue.
After pressing a key it shuts down.
It will boot in safe mode.
I did install win98 over the top of 95 but have the same problem.
If all else fails I willreformat and reinstall win98 but its a friends pc and he has nothing backed up.
Thanks for any help.