When installing Windows 7, the software will automatically set up an administrator account, which will later on be disabled (default behavior that also occurs when installing Windows Vista). Whenever you want to perform tasks under the administrator account with no UAC (user account control), you need to enable the admin account.
A word of warning first: it is advisable not use the admin account on a day to day basis, only enable it when you have to address some problem or issue that can only be fixed otherwise (guest accounts offer limited accessibility, but from a security point of view are safer).
To enable the admin account, follow this simple step by step:
Right click on Command Prompt -> Run as administrator -> type in the command
“net user administrator /active:yes”.
You might want to password protect you newly enabled admin account, so type in “Net user administrator password”. Replace “password” with the password of your choice. Log off after the command has been executed. When you login you will notice that the admin account has been enabled. To disable it once again, use the “net user administrator /active:no” command.
Alternative way of enabling the admin account:- Start -> Search -> type in “secpol.msc” -> Local Policies -> Security Options -> Accounts: Administrator Account -> double click to enable/disable -> Log off and log back in to see the modifications.