Windows 7: Keyboard language keeps changing although there are no other options

I have a fairly weird situation. I've done some (actually, a lot) of research but couldn't find a solution.

I have a Turkish keyboard. I prefer English windows, so I installed an English Windows 7 Home Premium 64-bit. I remove EVERY keyboard languages from Region settings under the control panel. The only keyboard that remains on that list is Turkish QWERTY keyboard, which is now default.

Now here's the problem: when I hit start and type something into the search box (such as regedit, msconfig, etc.) I see that the keyboard language is switched to English QWERTY although it is not set as default nor is it in the list. I ALT+SHIFT to change the language, which works in theory (says TR in the language bar), but English keyboard layout still applies. This, so far, only happens in the Start Menu Search box.



I'm a programmer so don't hesitate talking technical.

Many thanks in advance for your help!