If you use the Remote Desktop Sharing (RDS) feature of Netmeeting to troubleshoot user problems and perform remote administration, you don't want your clients turning RDS off.
To gray (disable) their ability to turns off RDS via the Systray icon, use regedt32 to navigate to:
On the Edit menu, Add Value name Nx, as a REG_DWORD data type. Set the data value to 1.
NOTE: Only administrators will be able to disable RDS.