Stuck at the beginning of Level 7

[mfw41]

Hello I'm stuck at the very beginning of level 7. As far as I figured out I have to get into a room to start the machinery but the door can only be opened when the power is on and I tried to jump through the open window to press that button but no go. So I'm asking you guys in helping me to get out of this room(and also to get the weapon that's underneath one of the machinery).