You can solve this problem by following the steps below.

1)In the directory where you installed LimeWire, you should see a file called "limewire.props." With LimeWire NOT running, open that file in a simple text editor, such as Notepad or Wordpad.

2) In that file, you should see a line that reads:

MAIN_CLASS=a.a.a.b.Main

Change this to be:

MAIN_CLASS=com.limegroup.gnutella.gui.Main

3) Once you have made this change, save the document in Text-Only format (make sure that it does not append ".txt" to the file name, so the file name should remain limewire.props and not limewire.props.txt).

Once you have done this, the next time you start LimeWire, you should not get this error message.

If this fails, I would recommend uninstalling LimeWire (from the Start>>Settings>>Control Panel>>Add Remove Programs window), downloading it again from our web site, and reinstalling.