My shift 2 enters quotations mark instead of at symbol

[Randy Scott]

I've hit something and now my 'at' symbol is a quotation mark. I've done it before but can't remember how to change it back (computer illiterate).

Please help!

 

[Phillip Corcoran]

Sounds like you somehow switched the keyboard layout from United States to United Kingdom.

With UK layout, shift + 2 key gives you quotation marks instead of the @ symbol.
The @ symbol is mapped to a different key on UK layout keyboards (I know because I use a UK keyboard of course)

Check your keyboard layout configuration in Control Panel > Region & Language > Keyboards & Languages (tab).
Then click "Change Keyboards"

Hard to see how you could have done that accidentally though?