You just plugged in your brand new Arduino (or generic) UNO, have loaded the IDE and are able to connect to it using led_Blink (bottom right-hand corner of IDE shows "Arduino/Genuino on Com port 4") in Windows 10...
Make sure your Windows Defender (firewall) allows access to the Arduino unit. Took my computer's (wonderful) firewall (Defender) several restarts to recognize the com port was trying to communicate.
Once you allow access, the card works like a dream. Hope this helps others.