This is a Windows system installed file with Windows File Protection (WFP) enabled.
There are 38 versions of netplwiz.dll in the wild, the latest version being 5.2.3790.3959 (srv03_sp2_rtm.070216-1710). The average file size is about 1.17 MB.
(Note, the behaviors below are for all versions of netplwiz.dll, select a unique version for details.)
Located in the registry at 'SOFTWARE\Microsoft\Windows\CurrentVersion\Shell Extensions\Approved'
United States installs about 44.24% of Map Network Drives/Network Places Wizard.