2 problems

[JusticeHero]

First problem being that today for the first time ever when I went to use limewire, something happened. something popped up saying that "One or more neccesary files appears to be invalid. This is generally caused by a corrupted instalation. Please try to downloading and instaling LimeWire again. If the problem persists, please visit www.limewire.com and click the "Support" link.
Thank you"
Thats the message and i did re-download it and this still popped up. I've had limey for 1/2 a year now and nothings ever happened.

As well, my second question being, how do I make it so if I were to delete limewire i could keep all my music, other then burning all the songs I got on to a dvd disc and then putting them back on my computer? Thanks in advanced for the help, sorry for being a noob.