Oh, it was working fine yesterday? That's relatively good news.
Are you positive nothing happened between the time it worked and the time it stopped working? Did Windows do any updates, or was any program installed or updated?
I recommend running AdAware and removing anything it reports, as well as going to java.com and making sure Java is updated.
Also, just to make sure LimeWire is reading that file, can you delete everything from in it (so it's an empty file, but it should still exist). Starting LimeWire should show, "LimeWire was unable to load. Please download and install LimeWire again." If that doesn't show (and LimeWire works), then it's not managing to read the file. I've put a copy of what the file should be on our server -- you can right-click on the link and choose 'Save Target As' and save it as 'launch.properties' in the directory that LimeWire.exe is in (same place as before). The file is at
http://www.limewire.org/temporary_fo...nch.properties .
Thanks. Hopefully we can figure out what's causing this and fix it.