Hi Carrie,
You said that you've tried everything, so I guess you've been through all the fixes here:
If LW Will Not Connect
When you deleted the preferences folder, did you have to go through the LW setup wizard all over again? If you didn't, then the folder wasn't deleted properly

In that case, make sure that LW's completely closed (check in Task Manager) & try again
Go to the gnutella.net file & hover your mouse over it...what size is the file?
Did you make sure to remove all other versions of Java before changing to another version & which version are you using now?
What's the model of your Linksys & are you using it with UPnP enabled, or is port forwarding set up?
Do this simple test for us. Using your browser go here:
http://www3.limewire.com:6346/ The page should say 'Your test worked!'. What happens when you go there?
Where are you trying to connect from (house, appartment complex, school, student accomodation, work, etc.)?
Also, just double check that the XP firewall is off.