That's only if you're using LW 5, if using LW 4 then it's different. LW 4 has no default blocking of sharing softw. & you can check extensions shared for LW 4 under Tools > Options > Shared > Types. To make sure they're not blocked from downloading check Tools > Options > Filters > Keyword.
For LW 5 it should be as that link above shows.

For preferences folder, depends on which Windows version you are using. Vista has a different location, as that link I gave earlier suggested. Also, if you started using LW several years ago, it might even be in the original location. Scroll back up to point #2 in post #1 of that thread. It 'might' be there under the name of .limewire instead of limewire.