Windows Can't Setup Ad Hoc Connection

Make sure your mobile device has support for the Ad Hoc network connection mode.

Please find additional information and troubleshooting notes at Microsoft's website: Microsoft Windows 7: Setup Ad Hoc Network

Once you've click create the ad-hoc network button, you should simultaneously scan and connect to this network from your mobile device. Since most android-based network doesn't support ad-hoc connections, you could also try to type "netsh wlan start hostednetwork" in command prompt to share your connection, which create an infrastructure network rather than ad-hoc network.

Make sure your wifi is turned on, i know this sound evident but sometime it's just too evident that we miss it.

If that still doesn't work, try to make one with the command shell by :

• Press Windows key (or hit the left bottom windows button)
• Write "CMD" in the search box
• right click the first option in "Programs" and hit the option "Run as administrator", that will open a black window
• Write netsh wlan set hostednetwork mode=allow ssid=myCoolNetwork key=qwerty123456789 then press enter
• If the previous command worked, write : netsh wlan start hostednetwork and press enter

If these two instructions worked without any error, you should get in your wifi list a new option called : "myCoolNetwork" with the password : "qwerty123456789"

(Can the person downvoting gives a valid reason so i can improve my answer ? Thanks.)