If you've disabled NFC on your Android phone, you need to switch it on via the system settings.
For Android devices:
- Go to Settings > Wireless & Networks > More, then tap on the NFC switch to activate
- If the Android Beam doesn’t turn on, just tap it and Select Yes
For Windows devices:
- Go to the Settings icon to turn on NFC in the App list
- Tap NFC More > Tap to Share Toggle on icon (to enable NFC Sharing and Pairing)