1 Answer

An administrator is someone who can make changes on a computer that will affect other users of the computer. Administrators can change security settings, install software and hardware, access all files on the computer, and make changes to other user accounts. To log on as an administrator, you need to have a user account on the computer with an Administrator account type. If you are not sure if the account that you have on the computer is an administrator account, you can check the account type after you have logged on by doing the following:

The steps that you should follow will vary, depending on whether your computer is on a domain or a workgroup. To find out, see "To check if your computer is on a workgroup or domain" in What is the difference between a domain, a workgroup, and a homegroup?

Show all
My computer is on a domain
My computer is in a workgroup
If your account type is not Administrator, then you cannot log on as an administrator unless you know the user name password for another account on the computer that is an administrator. If you are not an administrator, you can ask an administrator to change your account type. For more information, see Change a user's account type. 

Source: http://windows.microsoft.com/en-US/Windows7/How-do-I-log-on-as-an-administrator