I'm using Parallels Desktop v12, with High Sierra on my MAC and with Windows 8.1 running in Full Screen. I seem to have inadvertiently changed some setting and now a feature that I have been using for some time has gone. To switch from OSX to Windows, I used to be able to press CTL and right Arrow on my (Windows) keyboard, and vice versa, using CTL and left arrow to switch back to OSX. Now, in OSX nothing happens when I try to switch using the key combination and similarly in Windows when I have no applications open. When I have a Windows application open, CTL-Left Arrow moves the applications window to a different position on the screen. I have no Windows screen manager installed. Worse still, CTL-F no longer brings up the Find dialog box in an appication but opens a side bar to search the internet! What I have I done? Should I re-install Paralles?