To change the built-in Administrator password: 1. On the server, click Start, click Administrative Tools, and then click ...

To change the built-in Administrator password:
1. On the server, click Start, click Administrative Tools, and then click Server Manager.
2. In the navigation pane, click Configuration, click Local Users and Groups, and then click Users.
3. Right-click Administrator, click Set Password, and then click Proceed.
4. Type the new password twice, and then click OK.