Registry Errors

Ever since downloading the Firefox 'namespace' shortcut and Ffchrome, I've had an alert that my systems health was critically low and have had multiple high priority messages about registry problems that my system has been unable to correct. I am not very familiar with these issues and have not found a way to fix anything beyond deleting the Firefox shortcut (all system warnings began directly after that download) which has not seemed to rectify the problems. I would really appreciate any help you could offer. Thank you so much!