Try restarting the VMware Tools service inside the guest.
Also use this script by Luc to check if all prerequisites are met to run commands inside the guest via Invoke-VMScript:
http://www.lucd.info/2012/01/01/will-invoke-vmscript-work/
what I do know is vix is installed cause I tried to install it and it said a newer version is installed already.
What exactly did you try to install there? Just use the standard Tools images provided by VMware.