Professor Messer’s CompTIA 220-1001 A+ Study Group – September 2020Professor Messer’s A+ Core 1 Course Notes: Click here to learn about my Core 1 and Core 2 A+ downloadable PDF Course Notes. Professor Messer’s 220-1001 Core 1 A+ Practice Exams: Are you ready for your 220-1001 exam? Click here to learn about my 220-1001 Core 1 A+ Practice Exams. Audio Replay