Control Panel -> View network status and tasks -> Change adapter settings -> Right Click the connection that represents your Wifi -> Status -> Details
Find the entry 'IPv4 standard gateway', that should be the private IP of your router inside your home network. Copy that ip into your browser and open it. The control panel of your router should show up (in most cases). First check if all the settings there are correct.
Second, many router control panels show a connection status and if not connected error messages. Check what it says when your connection times out.
Another thing: Search for the device manager in Control Panel -> Hardware and Sound and open it. Find your wifi adaptor and right click it, choose Properties. Find the tab energy management, and untick the box 'computer can turn off this device to safe energy'.
All i can think of atm, hope this helps.