HOW DO I TURN OFF MCAFEE?

hi. i have mcafee antivirus plus an its too good. i cant download sht without it destroying the file as soon as i get it. for example i got the updated perx and when i tried opening it i got a message 'mcafee has just deleted another trojan from your computer' at first i was like @.@ wtf? then i seen a message saying perx could not be opened due to blah blah blah. anyway i need to figure out how to temporarily turn off mcafee. i cant uninstall caz it costed money to get it.

Open McAfee Security Centre
Click on 'Computer & Files'
On the right panel click on 'Configure'
The second panel down says 'Virus protection is enabled' - change it to 'Off'

It will then ask when you want to restart protection - either at restart, a set number or minutes or never. Pick whichever one suits your purpose.