Hi
DO you mean this reference to F11? It wipes your Hard Drive completely.
Turn off the computer.
Disconnect all connected devices and cables, Media Drives, USB drives, printers, & faxes.
Remove media from internal drives, and remove any recently added internal hardware.
Do not disconnect the monitor, keyboard, mouse, or power cord.
Turn on the computer and repeatedly press the F11 key, about once every second,
until the Choose an option screen is displayed, and then continue.
On the Choose an Option screen, click Troubleshoot, and work your way through the screens.