Question : Administrator and Run as Administrator Windows 7 - the difference

Can someone please explain the difference between
Running a program when I am logged in as administrator
And running the same program by choosing "Run as Administrator" when I am logged in as the same administrator user.
There is a difference but I do not understand why there is any difference
or what the differences are.
This is in Windows 7.
Thanks

Answer : Administrator and Run as Administrator Windows 7 - the difference

there is  no difference more or less. that function is supposed to be used by restricted user.
the only difference is not regarding ntfs permission, but the permission the programm will have on the system.
in vista and 7 allso running process have defined permission to write or modify registry. so a progra that run as administrator will have full access to the system.
in this way an administrator can choose wether to run a progrma with limited rights or with full permission.
hope this help.
paolo.