The problem is in this part:
I am logged in the administrator account.
There is no the administrator account, there are accounts with administrative priveleges.
Consider the following:
Company A has CEO_A.
CEO_A calls another firm, lets say company B, and tell then to sell stock.
B: responds with “Heck no. We do not follow order from you. Your title might be CEO but you are CEO of Company A and not from us. We only listen to our own CEO's".
You are logged in administrator on computer A.
You tell computer B to shut down.
B responds with the same "Heck no" since you are not logged in as administrator on B.
For this to work you need:
- Either some account which has administrative rights on the target computer.
For ServerFault I would expect this to be done via AD and via policies. (Then again, this question came from stackoverflow and probably should have been moved to superuser, not ServerFault.).
- The same username and password on the target computer (which would be a very bad habit, using the same password on multiple machines).