OK, I think I found it. In the PC net addict free app under the "CATEGORIES for Websites or programs..." menu, i see that taskmgr.exe along with other items are restricted, so I'm able to grant access to task manager again. I'm curious, what is the reason to restrict task manager? When I test it by turning off the restriction, then use task manager to kill NetAddictFree, the NetAddictFree does a nice job of restarting itself, so there seems like no harm to granting access to taskmanager?