Written by Daniel Mundy | 28 October 2009

Right click on the network icon in the system tray, and select "turn off notification of new networks"

Source: http://forums.whirlpool.net.au/forum-replies-archive.cfm/1131596.html

Seems like a hack to me, if anyone knows a better solution I'd love to hear it!

 

This can also be set via the registry:

• On a per user basis
  • Set the value "Show" (REG_DWORD) to 0 in
    HKCU\Software\Microsoft\Windows NT\CurrentVersion\Network\NwCategoryWizard
• At the system level
  • Create a new Registry key (without any value) NewNetworkWindowOff in HKLM\SYSTEM\CurrentControlSet\Control\Network\NewNetworkWindowOff