How to install a Firefox Addon with nsis

Question

How can I install a Firefox addon via nsis installer?

When I call Firefox with the .xpi extension it doesn't work and xpi extensions are not associated with Firefox either.

If I drop it to "C:\Program Files\Mozilla Firefox\extensions" then it tries to install every single time a user opened the Firefox. Never deletes the original xpi (potentially due to the Vista UAC)

Answer 1

By using the correct command line parameter :)

firefox -install-global-extension c:\extension.xpi

Refer documentation

Answer 2

Before Firefox 3.6 you could use the -install-global-extension parameter to install an extension. However it was removed in Gecko 1.9.2. Possibly the best method to install extensions now is to create a registry entry as outlined in the Adding Extensions using the Windows Registry page.