It depends what you use it for. If you use it to download copyright material without paying it is illegal. If you use it to download non-copyright material or you pay the copyright fee then it is legal. It is not the P2P software that is illegal.
are automatically protected by copyright, and you must not download or upload them via a P2P files-sharing system unless:-
1. The copyright has expired.
2. The copyright holder has consented to his/her creation being in the public domain.
3. You have paid for a copyright licence.
In general, you should proceed on the assumption that all music downloads/uploads via P2P software are illegal. There may well be some copyright-free files, but they will be the exception rather than the rule. If something is copyright free you are unlikely to have to go to the extent of obtaining it in this way.
Q: What's the difference between LimeWire Basic and LimeWire PRO?
A: Lime Wire offers two versions of its software: LimeWire BASIC, a free version, and LimeWire PRO, which is available for a one-time charge of $18.88. The purchase of LimeWire PRO gives users better search results, turbo-charged download speeds, connections to more sources, a guarantee of no ads or nagware, a special PRO only skin, personalized support via email and free updates for up to 6 months. The purchase of LimeWire PRO also helps to support an open-source movement that doesn't support itself by sneaking unwanted software onto users' computers.
I can't see how. click here The basic version is free but the Pro version is not.
You need to pay and then you get the Pro Download link.
"After your purchase is completed, you will also receive an email with a link to download future versions of LimeWire PRO. Your browser will be redirected to the LimeWire PRO download page. You must download and install LimeWire PRO on your computer in order for changes to take effect."