My mom got an Acer aspire V5 touch (windows 8) & it won't connect to the wifi. All my other computers, phones & PS3 will connect but not this.

I tried using my phones 3g (hotspot) & it wont connect to that either.
I reset my router(pressing down on the button or 30 seconds) & changed the wifi password. I also tried unplugging the router, nope..
I uninstalled mcafee using control panel.

It shows a yellow exclamation mark, says unidentified network with limited connectivity. Please help, this is such a headache!!