|Real mode dos support is dos without windows, the way it was before 9x came along. The dos commands found in 98 and to a lesser extent ME have been updated but do the same thing.|
ME is basically 98 without the booting to and exiting to dos options. Oh it has different hardware support--mainly more support for stuff you'd plug into a USB port, although not nearly as good as XP and later.
In both 98 and ME you could open a dos windows and use dos commands, although that was usually called command prompt since it was done within windows. I think the dos internal commands--those in command.com--were the same as 98 but some of the external commands--those run from their own files--were removed.
Most bios' have an option that allows windows to change some of the hardware settings--port addresses and IRQs for example--to suit its needs. If you opened a dos window and ran some dos software, it ran under the windows settings. But in 98 for example if you exited to dos and ran the same software it would run with the original bios settings. Sometimes especially with games it was difficult to get them to run both in a dos window and in pure (real mode) dos.
Both 98 and ME have LFN support. But in real mode file names get shortened to 8.3 format. I can't remember if a dos window had LFN support or not.
There may be other technical differences that I never paid attention to but that's the gist of it.
Riider's link explains it well too.
message edited by DAVEINCAPS