Thank you for your reply. I appreciate it very much. I deleted some files in Mac OS preference folder that you mentioned. seems like I could uninstall LimeWire and could re-install by LimeWire Installer, and the process made LimeWire connect with its network. And so far it works much faster and more comfortable than the one I used to install. I don't know why the problem I posted before happened, but once LimeWire software asked it cannot find the folder for downloading, where the downloaded files are saved. And I had 2 folders for downloading then. Maybe that kind of tampering files in my system folder could be the problem that prevent LimeWire from connecting the network. I will refer to your message when it happens again. Thank you for your message and time.