On my computer compatibility mood is under tools and internet options. I just click on the A/A in the upper left corner and have no problems. It pays to be careful about the adjustments one makes as they can create more problems than one already has. A good anti-virus program is a must. I use the free AVG one. As long as the A/A works for me I will not mess around trying to change compatibility settings. I have windows 8 on my computer.