in order to disable Direct Access on Windows 8.1, you can run the following powershell script (as administrator)
remove-itemproperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows NT\DNSClient" -name DnsPolicyConfig
Net stop iphlpsvc /y
Net start iphlpsvc
Write-Host "Press any key to continue ..."
$x = $host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")