It's Ubuntu 14.04 LTS (Trusty Tahr). Long story short, I uninstalled a lot of software by mistake. Among others I uninstalled Unity, Samba...even Nautilus, then switched to tty1 and installed all that I could think of, all thet I needed so far. The only thing that does not work is browsing the network from Nautilus or from Dash. Samba works, smbtree gives all networks, smbclient can access a Windows share and I even copied some folders from a Windows server, but when I try from Dash it says:
This location could not be displayed.
Sorry, could not display all the contents of “server (smb)”: The specified location is not supported
It was nice accessing Windows shares from Dash and if you would help me I'd like to get it back :)