Features of Workstation - in vCenter or vSphere? 5.5

I am doing a lab which requires to additional adapters to be created. http://boerlowie.wordpress.com/2011/12/15/building-the-ultimate-vsphere-lab-part-10-storage/

It is asking to use the Virtual Network Adaptor and then add this to a VM. I can't connect to the VM using workstation and have no idea why , keep getting "Permission to perform this operation was denied"

Can I add the new Adapters suing vCenter or vSphere and then choose "custom specific virtual network"? Again using 5.5

Thanks.