%HOMEDRIVE% vs. %ProgramFiles% vs. %HOMEPATH%: When should an Application choose which installation directory?

Some cross-platform packages like Ruby or Qt prefer %HOMEDRIVE% as the default installation path, Google Chrome uses something in %HOMEPATH%. What's the advantage and disadvantage of each choice? What's the best choice for a simple private application (i.e. a game, where the installation should work without administrator rights)? On the other end: What would be the best choice for an industrial application (i.e. a software that controls an industrial device, running on a computer that merely exists for that purp开发者_JS百科ose)?

If you want to ensure your app can be installed without Admin privs, install under %LOCALAPPDATA% - if you want to install system-wide, use %ProgramFiles%. Whatever you do, don't use %ProgramFiles(x86)%.

As a general rule I find it hard to believe that a single installation will work for multiple operating systems. From my understanding it seems that you would need multiple different installation files to handle each of the different file systems (not just installation directory, but the actual file system). This will span not just private, and industrial systems, but all business systems as well. Go to the download page for any software that is available for multiple OS and they will have a link for each one.