Hold control+alt+delete. Then when the task manger appears click on the second tab named processes. Then search the list for LimeWire. If you find it click end process. If a little window pops up saying are you sure click yes. Then restart your computer. If it still doesn't work go to limewire.com and reinstall it. This is what happened to me when this occured with limewire 4.11.1 so I just updated to 4.11.4 and everything was fine. Hope this helps.