Try deleting LW's preferences folder when LW's properly closed. See point 3 below (also point 2 if you've used much older LW versions in the past).
Fixes for LimeWire

Deleting that folder will kill all of your settings within options, you'll have to go back through afterwards & reset things to the way you like them

Ok so just to let you know...you're amazing. Hah. It worked. I can download stuff again. Thanks so much. I really appreciate it.

i have a question about that i have the same problem and i went to go delete the folder and the only file that looked similar was my LimeWire folder which was in my program files i went to delete it and it said cannot delete file: cannot read from source file or disk
what should i do?

The folder's hidden by default, so you'll have to show hidden files & folders to be able to see it

Go to My Computer, click on tools > folder options > view. Put a dot in the circle next to 'show hidden files & folders' > apply > ok. Now you should be able to find the preferences folder.

i did that and it wasnt there i also did the search and it wasnt there
i downloaded lime wire again thinking that might help and it didnt
it takes forever to search for music in general even bands that are by definition popular
ive been using limewire for so long since like version 1 and i have never had a problem with this, someone mentioned something to me about a brick wall at the bottom left hand corner
does that have anything to do with it?

Did you look for a folder in the old location of C:\Documents and Settings\your username\.limewire? Since you've used much older versions of LW, you'll most likely have a folder there too (that one's not hidden).
Otherwise, I'm stumped! You've gotta have a prefs folder

Can you give us your details, please?
System details - help us to help you

ill check there then because i have seen that folder