simulation - How to imitate servers (without loss of computing power)? -

i have production environment, running on 1 server. need run 2 instances of 1 software, each on "another" server.

is possible imitate more servers on 1 real server free? without loss of computing power , network flow in/out of real server?

edit: in words: want run 2 instances of same software on 1 machine. , need use function transport subinstance instance1 instance2. function possible use when instance1 on server instance2. need imitate 1 of both instances running on local on different servers.

i'm making assumption using windows, in case use hypervisor hyper-v if have purchased 1 license of windows may limited in can run in production capacity.

if mean software need run has 1 license typically not allowed virtualize either, seems answer legally not going able 1 license, assumptions may wrong, question wasn't clear enough.