You may login as Administrator and perform that "operation" or disable your User Account Control [UAC] by Start ->Control Panel -> User Accounts and Uncheck/untick the check box of User Account Control (UAC) to help protect your computer and click OK ad reboot.
What are you trying to do which requires "Run as Administrator">
You will need to log in with an Administrator account or you would need to disable User Account Control (UAC).
It is not recommended to keep UAC disabled but you can disable it temporarily.
Go to Start, click on Control Panel. Click on User Account.
You would need to move the slider bar to Never Notify.
You will need to restart your computer for the changes to take effect.
For more information on UAC see:
http://windows.microsoft.com/en-US/windows7/Turn-User-Account-Control-on-or-off
Hope this helps.