It's due to the type of installer. LimeWIre changed their installer so it doesn't work with the add/remove control panel. If you use the add remove control panel it will cause problems with an improperly uninstalled program; ie: not all components will have been removed from the registry, blah blah ... hehehe

Once you've been using Limewire for a few years you catch onto these types of changes. As these were important changes. I think for the better. Limewire tends to install much easier than it used to without as many side issues (ignoring java issues!) Keep up with the changes & you won't regret it.