When you attempt to hide Ncpa.cpl using the Hide specified control panel applets, the Network Connections applet isn't hidden.

Network Connections is a shell folder that Ncpa.cpl launches.

You can use a logon script to set the \{7007ACC7-3202-11D1-AAD2-00805FC1270E\} GUID Value Name, a REG_DWORD data type, at  HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\NonEnum to a data value of 1. You can use REG.EXE, built into Windows XP and Windows Server 2003, or from the Windows 2000 Support Tools:

REG ADD "HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\NonEnum" /V \{7007ACC7-3202-11D1-AAD2-00805FC1270E\} /T REG_DWORD /F /D 1

or you can use a Regedit.exe:

regedit /s %LOGONSERVER%\NetLogon\NoNcpa.reg

Where %LOGONSERVER%\NetLogon\NoNcpa.reg contains:

REGEDIT4

\[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\NonEnum\]
"\{7007ACC7-3202-11D1-AAD2-00805FC1270E\}"=dword:00000001

You can also create a custom administrative template file.