How To Make A Peace Sign With The Alt Key Why Are Symbols Not Showing Up On My Computer?

Why are symbols not showing up on my computer? - how to make a peace sign with the alt key

On my computer I can see some symbols like the peace sign with the ALT key made. I really want to see characters in my name, MySpace page made, but appears as a small square / rectangle.

Why is this so?
Not because I'm using Internet Explorer or because I was trying to see in Firefox and appears as a question mark.

Please help!