alright, try this then:

totally uninstall yet again...then move/rename all folders you have associated with LW....then install again and see if it starts up...if it does, then proceed to direct LW to the folders you used to download to/share from...

I'm thinking that perhaps you have something in your library that is freaking a new install out, or perhaps the simple size of it is hanging LW up...dunno, just a guess...