I just spent way too many hours trying to figure out why every blog post on the subject of using a wireless display claims there was a link to “Add a wireless display” in the Devices charm under the Project option but not on my machine. I recently bought a Samsung UN55H7150 television that had screen mirroring capability and my HP TouchSmart 15t laptop claimed to support wireless displays but for some reason I couldn’t make them work.
If you’re having this problem, I’ll save you the effort of figuring it out: you’ve got a virtual network driver installed that is mucking with this capability. I ran across a reference in a blog saying they had trouble after installing their company VPN software. I thought maybe it might be that but then I realized this hasn’t worked since I installed Oracle VirtualBox. I tried disabling the driver but that didn’t seem to do anything. After uninstalling VirtualBox completely, the option was again available.
I can’t tell you how many hours over how many days I lost to this as I would attempt to figure it out, get frustrated, give up and then try again another day but it was too many.
If the “add a wireless display” option is missing from your Windows 8 machine and you’re sure you have hardware capable of supporting WiDi or Miracast, look at your installed software and remove anything that added a networking driver.