If you’ve worked in a corporate or educational IT department where group policy is a strictly enforced bane of your existence, you are likely familiar with this issue. The High Contrast hotkey, and a vast, deep hatred for it.
Let’s start with some background. The High Contrast hotkey is a way for users who need such “Ease of Access” functionality to quickly toggle that mode so they can easily use the computer in front of them, then switch it back when they finish. It’s done by pressing Left SHIFT + Left ALT + PRINT SCREEN. That’s all well and good until you get in to a situation where group policy allows you to enable the mode, but not disable it. Now, it’s not just that the hotkey won’t toggle it off, but your company/organization likely also blocks access to the ability to change themes from within Windows Vista, 7, and 8’s Personalize control panel applet. So, how do you get around it? The registry!
I spent some time working on this one, testing many different portions of the registry, performing hive backups, modifications, and restorations. Eventually, I came with this REG file that entirely reverts the current user’s theme to the default Aero theme and restores the color values that change when you enable High Contrast mode. Simply merge the reg file while logged in as the affected user (which means you can run this in many ways if, say, an entire lab of PCs is modified by some prankster).
So, click here to download the REG file.