China DOS Union

I used the sys a: command to make a disk and booted from it.
After booting, when I run multiple programs it says there isn't enough memory.
What should I do?
(Additional question: when booting from this disk, after running a program (the kind of program like a game)
when exiting the program, it calls command.com on drive a:
how do I change this default path, for example to:g:\command.com )

You need to configure the memory. For specifics, please see the “Using DOS” section on the site. The way to modify the target path of COMMAND.COM is to change the COMSPEC environment variable.

Thanks