Is there a rule that only programs with installers go into C:\Program Files?

Question

In another question today, RBerteig mentioned that he/she always tried

to follow the rule that the only way to write to C:\Program Files is through a real installer

I have never heard of this rule. Where does it come from?

Answer 1

This is only done by convention. If you are working as normal user there is additional reason why writing to it trough installer is practical. That folder is read-only for standard users and writable only by administrators. Installer usually runs with administrative privileges.

Answer 2

This is not a rule... :)

This folder is a normal folder. It is only a convention to install applications to this folder on windows systems...

Answer 3

That is not a rule.

Personally, I divide programs into Program files and Program files2 (imaginitive, I know :) into which come programs which (installer or not) have all their settings in their directories, so I know what program directories I need to go through to backup them.

Answer 4

There is no such rule.

You can place any software you want into the program files folder as long as it's software you want all users of the machine to have access to.

This idea of a "rule" might have started out with Vista because of UAC. People started to notice that regular users don't have write permission to the program files directory. Only admins and Trusted Installer have write access to it.

Edit: cleaned up the preceding paragraph a bit.