watcom is a c compiler for windows, if i remember right old programs compiled for DOS with watcom compiler had a bug that made them report an error when trying to load on newer fast machines, usually machines faster than 200mhz, the bug is caused by some flow point claculations error in the watcom compiler, to fix it you either need to get an updated version of that programs, also i belive there are some TSR`s which are memory resident programs for DOS that catch the code in memory and correct the error or that actually slow down your computer so the error wont happen 🙂