You go to Control Panel and click on the language option.
I don't have an English keyboard (and I have a Mac) so I can't really give detailed instructions.
I found a link though:
http://www.online-tech-tips.com/computer
This is for Windows then which I assume you have.
The Swedish language should already be available so all you need to do is change the settings. Then the hard part is to figure out how the symbols have moved around. xDHow do I change the language on my keyboard to Swedish?
The following website has an online onscreen keyboard emulator that enables you to write in Swedish wherever you are in the world. You just write your text here and then you can copy and paste all of the text in your document.
http://www.gate2home.com/?language=sv%26amp;se