QEMM is a very well-respected memory management program that works for nearly
everyone. I had one of the few serious problems that I know of with it, and
that may be because I have a branching autoexec and many TSR programs. If you
have or plan to buy DOS6, you might try the new memory manager built into it,
rather than spring hard-earned $$ for another program; but I haven't used it so
I don't know about ease of use, etc. Even DOS5 has the rudiments available –
covered in the file of mine you downloaded; you might want to ask your friend
to help you with implementation…
Good luck.