The file nacmanager.plg is a type of dynamic link library file used by Symantec in their products, including Norton AntiVirus.  It is most commonly found in the Symantec Endpoint Protection version of their firewall and antivirus software.  This file is part of the Network Access Control (NAC) functions of the program.

Network Access Control protects your computer by checking the authentication of your network connection.  An error with this file may disable networking functions of Symantec products, possibly leaving your system vulnerable to virus attacks.  You may be able to fix the issue by reinstalling your Symantec software, but you should also consider cleaning your registry.

The registry is where Windows keeps track of its stuff.  Every file on your machine has an entry in the registry database that Windows uses when you run a program.  If there is a mistake in a registry entry, Windows won’t be able to find that file and your programs will not work.

ZookaWare PC Cleaner fixes that for you.  ZookaWare PC Cleaner cleans up your registry mistakes.  Rather than going through the thousands of entries in the registry manually, let ZookaWare PC Cleaner tackle the job and get your system clean again.