i know this might sound dumb but have u tried dragin the file to the recycle bin, or try login in as administrator or safe mode
also it seems like you are not on, but tha could be because of the different versions of folders. and are this your files?, since this part of the system even a non-administrator user can acces.
C:\Documents and Settings\<Your Windows Username>\Local Settings\Application Data\Microsoft\Messenger\<Your Passport Email>\Sharing Folders\