Question: A lot of software installation dialogs on Windows throw up a query to the installing user asking if this software should be installed for **all users** or the **current user**.

Why do they do this? Why not just install for all users? What is the real technical difference between the two options? I would like to know the difference in aspects like the registry, file execution permissions, files in the file system, start menu shortcuts and such.

Answer: 
Take a look at the following web site, it goes into pretty good detail on the differences of *all users* and *current user*:

[Installation types](http://www.tarma.com/support/tin5/using/installtypes.htm)

**Edit:** This is for a particular type of installation setup software, but the information here is valid for most installers with variations in their options prior to the compile stage.
I think the only difference is whether it'll put a shortcut in the all user start menu folder, or in the current user's start menu folder.