Dual citizenship is not permitted

I added a "Swedish" setting to our computer so I can use the extra Swedish letters... and when I changed back to the "English (United States)" setting, the computer didn't quite change back all the way. Picasa has gone entirely Swedish, so that my top toolbar reads "arkiv," "redigera," "visa," "mapp," etc. It's driving Cook crazy, but I'm kind of enjoying trying to figure out what the computer is talking about.