dlink 600L gives high priority to wifi devices

Hi guys, recently I faced a very irritating issue with D-Link Wireless N 150 Home Cloud Router DIR-600L.
Who ever tries to join wifi the internet speed on pc goes to almost nil where i cant perform anything.
How do I give 1st priority to PC or equal distribution of net speed to both pc n wifi devices.
I'm using MTNL broadband 2mb plan.

delete this thread........