Keyboard opens shortcuts

Hello, my keyboard isn't typing anymore. When I'm on the internet, certain letters open shortcuts (the h opens history, enter opens a tab with the same page, f opens file, etc.). Also, my mouse won't open links and when I click to type in Word, the mouse shows black bars.
I had just installed Dropbox when this happened (I couldn't type my name and password), while everything was fine before... I don't know if it could be related (I've uninstalled Dropbox since then).

I'm running Windows XP and no, my ctrl key isn't stuck :/

Thanks!
Configuration: Windows / Chrome 41.0.2272.89