Hi,
Yes you can have odd numbers of vCPU - we regularly run with 3 vCPU's. Being able to right-size VM's is one of the cool things about virtualization. Cannot do this with physical, i.e. needs to be 1, 2, 4, 8... etc.
Now to your other problem - it is due to the Windows edition you are running on the guest OS. Windows Server 2008 R2 standard only supports/allows 4 sockets worth of CPU which is why you can only see 4 in task manager even though 7 are provisioned. Since you are running vSphere 5 there is an option - cores per socket. Cannot do odd numbers now however you (VMware team) could change this VM from 7 sockets 1 core to 4 sockets 2 core, etc. This would allow Windows to use all the vCPU and continue to stay within your licensing. Actually this was an option with vSphere 4.x aswell but required an advanced setting to be changed. We did this on our SQL servers to limit licensing costs as a single (pre SQL 2012 licensing) socket license was for upto 6 cores. This can now be done at the VM configuration screen.
Kind regards.
Message was edited by: ThompsG