I would go into control panel>keyboard and see what keyboard is selected. Sounds like it is of a Foreign country. I know for a fact that the Shift-2 will give you " on an Italian keyboard. [ = è, ] = +, \ = ù, ; = ò, ' = à. And on and on.
Besides that, I can think of no other reason that your keyboard would screw up. If you have an American as well as a 'Foreign' keyboard installed, you can toggle between them with an Alt-Shift.
I hope this didn't confuse you more......