Hi fatima, I merged your threads together for this game. Please stay with one thread per game so we can follow your progress. You can find all your posts at My Place at the top of the page.
For the jetpack -- first, be sure that you are out in the main castle grounds, well away from the path and away from any buildings or structures. Then, place your cursor to the left of, and just slightly below, the halfway mark on the lever control. Then click-hold, and drag your cursor up a little. The lever moves straight to halfway.
Although double-clicking moves the lever to the quarter-mark, the game doesn't like that method and that causes the explosion -- assuming of course that the print is indeed correct.