You shouldn't need to re-install and if you do, the files will not be overwritten.
Are you connected - the button in the bottom left should be 'green' if you are.
If it's 'red' you're not connected, go to File>Connect.
Perhaps your searching too soon. Try searching when you get more connections.. Look in Tools>Statistics
Also..this was a good discussion on firewalls - take a look..
http://www.gnutellaforums.com/showth...5&pagenumber=2
Good Luck