MS-DOS versions 6.00 to 6.22 provide a program called MEMMAKER.EXE which can
automatically make adjustments to your system files to free up conventional
memory for you. You need an i386 or later processor and extended memory to
use it. Never run it under Windows! Memmaker is probably your best bet if
you are not too familiar with DOS but you might also like or need to tweak things
yourself. I'll show you some ways of going about freeing up conventional
memory below.
To find out what's in memory you can use "mem /classify /p" followed by
enter, this will list the memory usage of all the TSR's etc. allowing you to
locate those which are using a lot of memory and take appropriate action.
Firstly try to locate any drivers or TSR's which you don't really need and
remove them. You can also load HIMEM.SYS through your CONFIG.SYS file
then load required device drivers into higher memory using DEVICEHIGH and
required programs into higher memory using LOADHIGH (or the abbreviated
version LH). You must also have the line "DOS=UMB" in your CONFIG.SYS
file to do this.
If you still can't free enough conventional memory you could search the
Internet for smaller equivalents to the programs you already have.
Mouse drivers have smaller equivalents to the ones
supplied as standard for example. There's also at least one smaller
equivalent to Microsoft's MSCDEX.EXE if you look around.
The list goes on...