Hi bob mitchell,
You need to give some info on your set up:

OS (ie Windows XP etc)
What LimeWire & Java versions you use
Connection type (dial-up, cable etc)
Where you're connecting from (home, work etc)
Any firewalls you're using
Modem/router brand & model numbers

Did LimeWire work ok before you had work done on your computer? What work was done on it?

Have you had a look through the other stickies in this section? It's worth a look...might find some answers