Why "nmenu" from Netware 3.12 can not run ?

My company used Netware 3.12 as a Network OS long time ago. And some of the program was calling out by using the "nmenu" function to acts as a channel to call other programs which placed onto five volumes of harddisks. However, our company bought some new computer and the OS was Win2000 Professional edition. Some of the program can not be ran on the Win2000 Professional edition by login to the Netware netwrok. Some error messages would be display such as, "Too many files was opened" or "Source did not find" etc. I had tried to add some comment onto the config.sys file such as "files=120" but in vain. Actually, what is the problem of this error, is it about the mapping problem between Win2000 Professional and Netware 3.12 ? Thanks !!

Ben