Lag on low requirement game despite godlike PC

Got a new computer, 4x the specs of my old computer. (now have 16 GB RAM, 2GB dedicated NVIDA graphics card, 3.8GHZ processor.

Cant run dota 2 at above 5 FPS, my old computer could run it at 60.
task manager says the process is set to high and i’m only using 30% of my CPU and 23% of my memory, despite that still like 5 FPS.

windows 8.1