If you live in a library district who participates in RAILS (Reaching Across Illinois Library System) you can now get your actual high school diploma and a career certificate completely online. Participating libraries may offer "free enrollment to a limited number of qualified adult students within their service areas." The online learning platform is provided by Gale Cengage.
Career Online High School is a legitimate and accredited program that community colleges will have a tough time competing with. You can actually transfer-in credits that you have already completed from your former high school(s).