I have had similar problems with NTLDR in the past and it had to do with installing the file incorrectly. The file just up and disappeared and when I went to put it back I didn't copy it properly. Personally I would say that you have some sort of virus, not necessarily LS related if you got LS from a respectable site. I would switch back to explorer and troubleshoot and fix your NTLDR problem and then try and switch back to LS. Again...normal LS will not touch these files. The only system file it alters is the registry just to make itself load as the default shell. Good Luck!