I was under the understanding that installing Firefox wrote to the C:\program files (x86)\ folder and put registry entries into HKLM, therefore on a locked-down workstation a user would have to have Admin rights to install it. I've also always thought I could check HKLM\Software\Mozilla\Firefox to determine whether Firefox was installed on a workstation. However, I've just encountered a user's machine where they have no HKLM\Software\Mozilla\Firefox registry key (or the Wow6432Node version) and there's HKCU registry keys like this which make me think it can, like Google Chrome, be installed by a non-admin user to their Users area of the machine:
[HKEY_CURRENT_USER\Software\Mozilla\Mozilla Firefox\31.0 (x86 en-US)\Main] "Install Directory"="C:\\Users\\ausername\\AppData\\Local\\Mozilla Firefox" "PathToExe"="C:\\Users\\ausername\\AppData\\Local\\Mozilla Firefox\\firefox.exe"
Is this normal and how is this happening?
UPDATE: I'm not really looking for how I can do it, but rather how the user would have installed it like this. My software needs to recognise if Firefox is installed, so I want to understand the different ways this is possible.