Proper OS practice is to operate on an account that does not have admin priveledges, so if something gets corrupted, you can log onto the adnim account and see if things still work. If you wreck your main user account that is also your admin account, sometimes a complete OS re-install may be necessary if you haven't cloned you drive before the suspected corruption took place.
On my system, I am the only user, but I have two accounts set up. An Administrator Account, and my John Account (w/o admin priveledges). I use the computer for daily use when logged into my John Account, but do all my updates and mainatance logged into my Administrator Account. It's just a good practice to keep you daily use account isolated w/o admin priveledges so a corruption does not effect everything.