Freeing up memory for DOS program in Win

I need to free up at least 600k of conventional memory to run a DOS program. I have tried all the suggestions of the software vendor including environment specs.I have entered all the lines in autoexc.nt and config.nt the vendor suggested. I have also entered the recommended settings for the program shortcut. The machine I am trying to run this program on is a Dell Optplex 110. I have tried reinstalling 2000 without the Dell programs. We are looking at purchasing additional machines and would like to run Win 2000.