Seemed to work fine a month ago..no lock - down -- should have admin rights - checked settings and no issue there ... Is the only solution to reinstall?
If you are a local admin, that doesn't mean that you by default have full rights on all folders on your C:\. Does other output formats work in that location? You may want to look at the folder security settings and give regular users full access to that folder. (As you normally execute all applications as a user and not as an admin.)