I have firefox in start menu, but there is no "properties" like in windows. how to find out were firefox is installed and how to check path of link in menu?
(I suppose you still don't use Unity but Gnome 2.)
That's a bit annoying in Gnome. What I do is, I click right and choose Add launcher to desktop. Then you have the launcher on your desktop and there is a context menu entry Properties (so again click right on the new file on your desktop and then Properties). This dialog will present most of the available information from the launcher.
An alternative would be to right click the application menu and choose edit. There you see all entries and you can also select Properties.
If you really want to find out the whole path for firefox, this shell command might be useful:
This returns the full path to the file, which is executed when only
Note that a launcher file is just a text file with the ending .desktop. You can drag and drop it to any text editor if the property dialog doesn't provide enough information.
If you want to find all the places where your firefox is installed, including executables, libs, user settings, use