okay so this is my first pc build, and i was installing cpu. it went okay until i put on the cpu cooler. Its AIGO DARKFLASH SHADOW CPU Cooler. i tried to mount it but it seems it wont mounted well, i had to apply pressure (it was firm) to mount it. the screw wasn't all the way down because i thought it was super firm already. the questions are, is it really hard to install cpu cooler? should i apply pressure to install the CPU Cooler? will i damage the cpu if i put too much pressure in it? please help, im in the middle of a build here. thankyou so much.