Free Comptia A+ Test OS Study Guide & training aids for A+ OS technologies exam. ProProfs.com is a provider of free CompTia A+ Test study aids including free practice exams, notes etc. Our free notes on a+ operating systems exam serve as study guide covering all A+ OS topics on just 4 pages. Study for the A+ OS certification test anytime and anywhere with these portable A+ notes. Download these Free OS cheat sheets for the A+ Test now! ProProfs.com also offers free practice exams, practice questions, study guides and more for the A+ certificaiton exam at: [url removed]