4.2.3 Constants Constants can also be used in the InstallDirattribute. Note that some of the new constants will not work on every OS. For example, \$CDBURN_AREA will only work on Windows XP and above. If it's used on Windows 98, it'll be empty. Unless mentioned otherwise, a constant should be available on every OS. \$PROGRAMFILES , \$PROGRAMFILES32 , \$PROGRAMFILES64 The program files directory (usually C:\Program Filesbut detected at runtime). On Windows x64, \$PROGRAMFILES and \$PROGRAMFILES32 point to C:\Program Files (x86) while \$PROGRAMFILES64 points to C:\Program Files. Use \$PROGRAMFILES64 when installing x64 applications. \$COMMONFILES, \$COMMONFILES32, \$COMMONFILES64 The common files directory. This is a directory for components that are shared across applications (usually C:\Program Files\Common Filesbut detected at runtime). On Windows x64, \$COMMONFILES and \$COMMONFILES32 point to C:\Program Files (x86)\Common Files while \$COMMONFILES64 points t...