Entering Extended Characters with the U.S. Keyboard

Turn on Num Lock and use the number pad on the right side of the keyboard.

To enter ANSI extended characters

To enter OEM extended characters

Press ALT followed by the ASCII code.
For example, to enter a mu sign (m), press ALT and then 0181 for the ANSI 1252 extended character, or press ALT and then 230 for the OEM 437 extended character.