How Do I Install IBM PC-DOS 2.1 on The Hard Drive

[modem7]

If i remember correctely the low-level format was done with the debug command.
enter "debug" on the prompt.
dcs:c800<enter>
g c800:5<enter>

That is correct for some XT-class controllers, but not all.

 

[modem7]

Problem resolved

Problem resolved

Note that the OP raised a related thread, and the problem was resolved in that thread.