Answer:
If your using windows XP or higher, turn your computer off and then reboot. When the computer turns back on, continuously press the F8 key until a screen pops up that will let you boot your computer in safe mode.
When the computer successfully boots in safe mode, click on the start menu and then click on Run...
In the search box type " regedit " and press enter.
Then on the right part of the window scroll up/down until u find your Internet security, right click on it and click on disable, then shut your computer off.
Then restart your computer normally and all the sites that were blocked will be unblocked.