Starting this morning, my Windows 7 is opening most applications in Vim (Vim is my editor of choice). The following is an itemized list of this bizarre behavior. From Start menu, most applications display the Vim icon (screen shot below). From Start menu, most applications open in Vim: NotePad (screen shot below) cmd.exe (I have not found a way to open command line) Paint Internet Explorer Chrome browserFrom Start menu, these applications open normally: Services control panelControl Panel opens, and menus within Control Panel navigate normally. From Control Panel, most applications open in Vim: Edit environment variables for your account Edit the system environment variables View event logsFrom Control Panel, some applications work normally: Make a file type always open in a specific program Set your default programsExplorer opens normally right click Start > Open Windows ExplorerFrom Explorer, executable files display the Vim icon and open in Vim (screen shot below): C:\Program Files (x86)\Google\Chrome\Application\chrome.exe C:\Program Files\Internet Explorer\iexplore.exe %windir%\system32\mspaint.exe C:\ProgramData\Microsoft\Windows\Start Menu\Programs\AccessoriesFrom Explorer, application files open normally: .html files open in Chrome browser (file association) .jpg files open in Windows Photo Viewer (file association) .jpg file > right click > Open with > PaintScreen shot capture works normally Alt+PrintScreen I rebooted twice, but it didn't change anything. How Can I trouble shoot this and get my applications to open normally again? Start menu shows Vim icons for most applications: Most applications open in Vim, here is Notepad opened in Vim: From Explorer, executable files like chrome.exe open in Vim: Thank you.