windows 8.1 not detecting Android phon

Up until now, I’ve been able to connect my Android phone to my Windows 8.1 laptop to transfer pictures and general files between the two. The laptop no longer detects the phone when I connect it via USB cable. USB memory sticks are still recognized, but the phone isn’t. Advice on Windows forums suggest turning off Windows Firewall. When I try to do that, I see the message, “These settings are being managed by vendor application Norton Internet Security.” I’ve tried various approaches to disabling the firewall with no luck. The NIS software on my laptop is up to date; I’m not running any Norton software on the phone. Any suggestions on how I get NIS to temporarily relinquish control of the firewall?