AC is when the electrons flow in two directions, from the positive to the negative terminal and from the negative to the positive terminal, 'alternating' between the two directions. A lot of people think of electron flow as electrons moving along a wire freely like cars go down a highway.
To check the status of protected mode, choose File > Properties > Advanced > Protected Mode. Protected mode is enabled by default. To specify the settings, do the following: Choose Edit > Preferences. In the Categories list on the left, select Security (Enhanced). In the Sandbox Protections section, select or deselect Enable Protected Mode At Startup. Enable Create Protected Mode Log File to record events. The changes take effect the next time you start the application.
Win7 - IE8 - Protected mode appears to be 'Off' (UAC On) I'm using IE8 on Windows 7 (64-bit) and I just noticed that according to the status bar the protected mode is turned off. I had a look at the Internet Options > Security tab and the Enable Protected Mode checkbox is checked. The UAC settings is: Default - Notify me only when programs try to make changes to my computer. I'm not logged in with the Administrator account but with my own account (Administrator type).