message load error press any key to reboot

been using win98se for many yearsbut recently could only use scandisk in safe mode till someone on this forum told me how by ctl alt del eliminate all but 2 programs and was able to use win scandisk again. unfortunately the next day i got this message load error and could not get even into safe mode anymore .had to get rid of win 98se and buy winxp as they said the drive was ok .everything now works fine but does anyone know what could have caused this ?thanks frank