Nostalrius Begins - Quality wow vanilla realm (1.12)

So i currently have two setups of computers, both are pretty high end and im sitting on 100/100 fiber. Nostalrius is working perfectly fine on my computer but on my girlfriends computer the game gets insanly high MS spikes reaching up to 5-12k MS after having played for a couple of minutes. This problem began a few days ago and has never occured before in the past year. I've done a virus scan on the second computer and it looks clean the only programs installed on the computer is pretty much WoW with Nostalrius... The game is unplayable, any suggestions?