[SOLVED] Took cpu cooler and fan off, can't install them back on

Solution
Please post a picture of the motherboard and socket WITHOUT the CPU cooler in the way, so that we can see the holes that the screws are supposed to fasten into. I suspect that on this design there was nothing holding the backplate in place once you removed the CPU cooler and you will likely have to either take the opposite side panel off to position the backplate in place again, or if it is a case that does not afford access to the back of the motherboard you may have to actually remove the motherboard, reinstall the CPU cooler while holding the backplate in place, and then reinstall the motherboard.
Please post a picture of the motherboard and socket WITHOUT the CPU cooler in the way, so that we can see the holes that the screws are supposed to fasten into. I suspect that on this design there was nothing holding the backplate in place once you removed the CPU cooler and you will likely have to either take the opposite side panel off to position the backplate in place again, or if it is a case that does not afford access to the back of the motherboard you may have to actually remove the motherboard, reinstall the CPU cooler while holding the backplate in place, and then reinstall the motherboard.
 
Solution
Please post a picture of the motherboard and socket WITHOUT the CPU cooler in the way, so that we can see the holes that the screws are supposed to fasten into. I suspect that on this design there was nothing holding the backplate in place once you removed the CPU cooler and you will likely have to either take the opposite side panel off to position the backplate in place again, or if it is a case that does not afford access to the back of the motherboard you may have to actually remove the motherboard, reinstall the CPU cooler while holding the backplate in place, and then reinstall the motherboard.

Yep, it was indeed the backplate, thanks a lot