Flash messing up Safari and MSN?

[toolate]

A couple months ago, I was trying to install the new version of Flash. After having some trouble with that, I went on a site that told me the best way to do that was to just reinstall the current version of Flash I had. Fast forward an hour, Flash is deleted, new Flash still wont install and now Safari, Mac Update, MSN Messenger, and AIM dont work. Is this all connected? How do I get Flash back if it wont install? Thanks