If by "jammed" you mean it's non operable then I'd suggest .. well .. I'd have to think about that one. But - if you're implying that every time you start up your Internet Explorer it's always in that position and you're still able to maximize, browse, type in it, etc then I know how to fix such a problem :
Step 1: Open up your Internet Explorer.
Step 2: Now, it should look as it does in your screen grab.
Step 3: Maximize it or form it to the position you desire.
Step 4: Exit out of it and while you're doing so press and hold the CTRL key.
.. .. ..
Step 5: Success!