Answers: Need more info on your question. Are you running two (2) separate instances of VMware Server? one on Windows and one on Linux? Or are you in fact referring to an ESX host as your Linux instance?
If the latter is the bag, you stipulation to use the VMware converter product and can port from Server product to the full blown VI3 infrastructure.
If explicitly not the bag, you should know how to use something approaching WinSCP to copy from one to the other.