Windows 7 has got an annoying feature that categorises network connections to be public, home or work networks. This might work for others but it has never worked for me. Even worse, for some reason the link that usually allows the user to change the network type sometimes is not available.
Microsoft even has got Knowledge base entry KB2578723 for that problem, which unfortunately didn’t work for me. I could change the current network, but after a reboot it again categorised the same network as unidentified network and public.
The solution is described in this article on sevenforums.com. Either use the Local Security Policy editor or RegEdit to change the setting how to treat unidentified networks. This setting is usually missing from the registry, so the keys must be created first. The easiest way to do that is the .reg file you can download from the page linked above. It looks like this:
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\CurrentVersion\NetworkList\Signatures\010103000F0000F0010000000F0000F0C967A3643C3AD745950DA7859209176EF5B87C875FA20DF21951640E807D7C24] "Category"=dword:00000001
As I said: the registry keys don’t exist by default. Creating them manually is difficult because of the long number Microsoft chose to use, so it was either the Policy Editor or the .reg file for me. I took the Policy Editor approach but later verified that it created the registry entry shown above, so it’s probably safe to just use the .reg file.