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.
Windows Defender is enabled by default to start protecting the computer in real-time against spyware, adware and other types of malware. However, the program does not scan or protect against viruses. You will need to install an anti-virus program to get full protection against all threats. The Windows Defender download is free for all XP, Windows 2003, Vista and Windows 7 users. Do not buy Windows Defender, because Microsoft never sells it. Any supposed vendor is scamming you.