Before diving into the "download" aspect, it is crucial to understand the technology. Miracast is a peer-to-peer wireless screencasting standard created by the Wi-Fi Alliance. Essentially, it creates a direct Wi-Fi connection between your Windows 8.1 laptop/tablet and your TV or display adapter (like a Microsoft Wireless Display Adapter or Roku).
Open PowerShell and type Get-NetAdapter | Select Name, NdisVersion . Your NDIS version must be 6.3 or higher . miracast download for windows 8.1 free