I've often had the need to figure out which vmware-vmx.exe process (on a Windows VMware Server host) matched which virtual machine. Maybe a development machine has locked up, or otherwise won't respond to VMware server shutdown requests... it happens to me semi-regularly. I found the answer here. You can use the SysInternal tool "Process Explorer" to see what command line argument has been executed for each process. In the case of vmware-vmx.exe, the virtual machine client name is in the command line executable, so you can figure out which VM matches the process.
Genius. Thanks a lot rsa911!