Plutonium

Nope, I tried re-installing the game and restarting the PC, none of them worked

Nah, I got a ryzen 3600 and gtx 1660 super, not a slow pc

when I click over online it stays loading forever, then eventually it says "The Call of Duty Black Ops II servers is not available at this time. Please try again later". It is not my internet, nor the server, my friends play while I stay on the loop. Other times it just works fine thought. I don't know what the issue might be, just happens sometimes