Cannot change "network's location"

Hi,
My development system is cut off internet at the router. As a consequence it gets no response from the DHCP server. This is no drama as it is configured with a fixed IP address.
It, however, makes Win7 declare connection as "Public". I used to be able to invoke some network function like "Map network drive" which would complain that "Network discovery" was disabled. I would then enable it and after a short while all my computers would show up.
Recently I had to re-install Widows 7 and must have done something wrong because this method does not work.
Communication still works except for "Browsing". I still can map network drive by typing "\\Nas\Photos" but Explorer under "Network" shows only one system - itself. When I tried to change location through "Change homegroup settings" (one shot only) it showed the proper dialog box with three options but it complained that it could not chane it.
When I look closely on my "Network and Sharing Center" dialog box I can see that "Home network" is not underlined while on most examples IT IS!
Any advice will be appreciated.

This is a very common problem which has a few possible solutions most of which are outlined in the link below. It can help to type the default gateway into the IPv4 properties Advanced settings as described in the link.

There are a few other possible causes and solutions talked about in the comments section in the link below. :)

Windows 7 Unidentified Network, Limited Access, No Internet Connection Problem Resolved