Open Windows Powershell as Administrator
Copy and paste the code below in Powershell:

====================================================================
$bytes = [System.IO.File]::ReadAllBytes("C:\Program Files\Nitro\PDF Pro\14\NitroPDF.exe")
$bytes[0x424385] = 0x01
$bytes[0x42439B] = 0xFF
$bytes[0x42439C] = 0xC0
$bytes[0x42439D] = 0xC3
$bytes[0x4245C2] = 0xB0
$bytes[0x4245C3] = 0x01
$bytes = [System.IO.File]::WriteAllBytes("C:\Program Files\Nitro\PDF Pro\14\NitroPDF.exe",$bytes)
====================================================================

Press Enter
Done NitroPDF.exe in now activated