All my shortcut icons have been changed to LNK in windows 7

Issue: 

All my shortcut icons have been changed to LNK files and I can't open any software

Solution:

• Click on Start > Run > type "regedit" and press the Enter key
• Navigate to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.lnk\ .
• Delete user choice folder, close registry editor and restart your machine.