Basically this means that the utility you are trying to run is from
a different version of DOS to that which you currently are using.
You should either obtain the appropriate utility for the version of DOS
you are using or boot your computer with the version of DOS
that the utility requires. Be warned that the later option could cause
you problems due to incompatibilities between the two versions of DOS.
There is a third way of running the utility, that is to use setver to
fool the utility into thinking that it is running under the intended version
of DOS. Please refer to the ** DOS Reference **
section to see how setver is used.