I had this problem for a couple years. I tried all the internet tips like power settings, updated the driver etc. Finally edited the wifi adapter settings and now it works properly for the first time. If only I'd have done it sooner. It may not work for you but might be worth a try. Good luck.
Steps: Control Panel System Device Manager Qualcomm Atheros AR 956x Wireless Network Adapter Right click / properties Changed 3 settings: Receive buffers to 512 Ensure transmit buffers are also 512 Scan valid changed to 120 Wireless mode selection changed from 5 to 4 (don't need b) Save and close Restart if no change Cross fingers