Nothing can replace a good old ethernet cable when it comes to realtime-traffic applications!
If really only that one computer got a problem and you can't use an ethernet cable I'd suggest trying out these four quick to do things:
1.) If enabled, disable QoS in the settings of your your wifi adapter. In my experience networking applications can benefit from deactivation of this option.
2.) Try deactivating all power/energy saving - related settings for your wifi-card.
3.) Just for the fun of it (if you haven't done this already), try connecting the computer with your router via cable temporarily. Maybe it's not in the hardware but in the networking stack of your computer?
4.) If you haven't installed any drivers but let Windows do everything: Try installing the latest drivers for your Mainboard and your graphics card.