Method 1:
Hit Windows+R to bring up the Run box. Type the following in the box and click ‘Ok’.
runas /user:Admin taskmgr
‘Admin’ is the name of the user with administrative privileges. It might be Admin, Administrator, or any other name. You will need to know the name of the user that has admin rights before you run this command. You will also need to know the admin password.
Once you click ‘OK’, it will open a Command Prompt window and you will be asked to enter the password for the admin account.
Method 2:
Alternatively, if you don’t want to use the run dialog box, type in ‘taskmgr’ (without the quotes) in the start search box to bring up the Task Manager’s EXE file, right-click it, and select ‘Run as administrator’. You will still need to enter the password for the admin account.
The advantage that the first method has over the second one is that you can use it to run the Task Manager as any other user by simply replacing the ‘Admin’ name with the name of different user’s account.