Your prefs will either be in C:\Documents and Settings\your name\Application Data\LimeWire (this is a hidden folder, so you'll have to show hidden files & folders to see it!
or (if you've been using an older version) it could be in C:\Documents and Settings\your name\.limewire

Go through tools > options in LW & make sure that you know what all your settings are.
Close LW & make sure it's really closed.
Delete the folder.
Now open LW again & go back through tools > options, reset your options the way you like them.
Give LW a while to settle down (say 1/2 hour) & see if it behaves itself

Sorry - In Docs & Settings/User/ there is an "Application Data" folder and there is a ".limewire" folder. There is no "preferences" file within .limewire. Do I delete the entire .limewire folder ? If not - what exactly do I delete?
Thank you - sorry for being a pain. For some reason this is just not clear to me !

Yes, delete the .limewire folder