For security reasons, the Windows 7 system Administrator Administrator account is disabled by default. When you need to use it, it's really easy to open it, and it doesn't require complex operations.
Method One: Enable Administrator from System Management
1. Open the Start menu, right click on "Computer", select "Manage" NOTE: If the confirmation window pops up, enter the account name and password with administrator privileges \ or click Yes to allow to continue
2. In the Details window on the right, right-click on "Administrator" and select "Properties"
3. In the Computer Management window, navigate to local Users and groups, and then click Users. Click to expand the Users item
4. By default, the "Account Disabled" item in the Administrator Properties window is checked. We need to uncheck it and press OK to save the changes.
Method Two: Use the command prompt to enable Administrator
1. Click the Start button and type cmd.exe in the Start search box. When the corresponding program pops up, right-click and select "Run as Administrator" Note: If a confirmation window pops up, enter the account name and password with administrator privileges \ or click Yes to allow to continue
2. When the command window opens, type net user Administrator/active:yes. Press the ENTER key when you're done. See the "Command completed successfully" message indicating that the system administrator Administrator account is enabled
Precautions
Similarly, if you want to deactivate the system Administrator Administrator account later, type the command net user Administrator/active:no.
How to find a real administrator account in Windows 7