You're correct, Inland. MSE is strictly anti-virus. carlahelp, isn't Avira an anti-virus program? You can't run both Avira and Security Essentials at the same time. Anti-virus programs do not play well together. The only other thing I would add is the free Malwarebytes to run every now and then to make sure your anti-virus didn't miss something.
The only thing I use the registry cleaner in CCleaner for is after I uninstall a program to get rid of stray registry entries.