Do you know that your Windows 7 and Windows 8copy comes with an hidden Administrator account, this account has access to all files and folders and there is no User Account Control for this account. Actually this account is used by experts if your computer is not working properly.
Well of you too wanna take control or do something in your computer which need admin privilege then you can enable this account and do whatever you wanna do.
Before we enable this let me tell you, Its not Recommended To Enable This Account, And you Should Not Enable It Until Your Really Need It.
Launch your run command by pressing Win+R and then type lusrmgr.msc,
Now it will open your Local Account Manager,
Here select the User from left side and then on right side double click on Administrator,
It will launch its properties, Just uncheck the option saying Account is disabled,
Click Apply and then on OK and you are done.
If you wanna set password for this account then right click on Administrator and click on Set Password.
Now just log off and login with Administrator account