There is a very good chance then that you have just made a small mistake when installing and starting to download.
First of all. Did you by any chance choose to not download without a licence ?
That will render most downloads useless. If so go to
Tools>Options>View>Popups and check the revert to default box
Then press apply and ok
then go to Tools>Options>Searching>Basic and uncheck Show Licence Warning
Then go to Filters>Content and uncheck contentfiltering
Press apply and ok
Then have a look at this thread before trying to download anything
How to find music
If your Limewire still doesn't work right then post back in this same thread
Good Luck