In Windows Windows XP, Vista, or Windows 7, click the Start button, point to All Programs, point to Accessories, point to System Tools, and then click Character Map. If you are using Vista or Windows 7, you can simply click on Start, then type Character Map into the search box above the Start button and choose Character Map when it appears near the top of the list.
When the Character Map appers it will look like this:
Find the character that you want and click on it. This may be a foreign letter, a degree symbol, a registered trademark symbol, or many others. Then click Select and then click Copy. The symbol that you want will be copied to the Windows clipboard. Then you simply go back to your email program or your document and click on Edit, then Paste and the chosen symbol will appear in your document.
If you use that symbol a lot, you can also use its shortcut key to put it in any document without opening the Character Map every time you want to use that symbol.