I would follow Linjos advice and have a read of the evaluators guide.
You specifically mentioned that you have installed ESXi which is good - but have you also installed vCenter Server in a Windows environment, or are you using the Linux vCenter appliance that VMware supply? I would assume the IP 192.168.221.131 is the IP of your vCenter Server? Can you see the vCenter server in your domain too?
If you are still struggling then take a look at this KB referenced in my original post: