Problems after uninstalling McAfee and installing Norton Antivirus

I uninstalled mcafee that came with the computer and installed norton antivirus. Now about the only thing I can do is long onto the internet. When I click on various icons a message appears to the effect, " File cannot be found; please select search and type in the file correctly that you wish to access." I believe all my programs are related to mcafee and when I uninstalled it is when all my problems happened. Is is possible to reinstall mcafee that came with my computer, thus eliminating my problems or have I lost all my files on my computer and need to reinstall all my software?
Thanks
Patrick