I installed Norton Security Deluxe (2015 release) on four PCs last year. The Norton product was configured to update itself to new version or patches and did so without problem a few times over the course of the subscription. The subscription (1 year) expired in August 2016, we did not immediately renew, and it began to notify "deactivated" 30 days later. One of the machines is running XP Pro (32-bit) in a server role (SQL). This machine became extremely laggy.
All essential or background services appeared to function normally but using the GUI to launch an app, Windows Explorer navigation, opening folders, open Control Panel, and dialogue boxes would lag by a full 12 to 14 seconds before responding. e.g. click start button, the mouse would move but nothing else responded for 12 to 14 seconds before the start menu would appear. Open a folder, 12 to 14 seconds later it would open. During that 12 to 14 seconds the mouse would move but could not select anything else. I did not at first realize it was Norton responsible for this, I suspected other causes such as bad sectors being handled, or even CPU throttling due to overheating but could find nothing (I checked). No errors or bug checks were being recorded in Event Viewer.
I tried to uninstall Norton through the included uninstall feature (Add/Remove programs) and even it seemed to hang so I downloaded Norton Removal Tool and ran it. It took about 40 minutes (compared to about 3 min normally) but finally completed and I restarted. As soon as Norton was removed and all Symantec services (e.g. NS.exe) unloaded, this lag or hang was gone, PC performed normally again.