This may help:
Go to Control Panel > All Control Panel Items > Network & Sharing Center > Change adapter settings (in the left pane), right-click on the connection you‘re using > Properties > Networking Tab. Now remove the tick from the IPv6 box. If it makes no difference or causes problems it is completely reversible by ticking the box.
Also, click the Windows Orb (Start), type devmgmt.msc and press Enter. Expand Network Adapters > double-click the wireless adapter > Power Management Tab and make sure the check box is cleared against ‘Allow the computer to turn off this device……’.