UPDATE: the Adobe link initially referred to in this post is not updated, so I compiled together the required files in this zip file. Download the updated files and copy them to the location noted in Step 3 below. Current version: Adobe Flash 10.3.

As I work in a restricted Windows environment, most of the software I installed on my own is not updated automatically. Firefox is an exception – however its plug-ins are not, and Adobe Flash Player lagged behind in this process.

Since the ActiveX plug-in for Internet Explorer is useless in Mozilla Firefox and downloading an installer requires administrative privileges to successfully complete the installation, an alternative course of action is required, but fortunately this path is accessible.

Tested on Firefox 3.x and Flash Player 10.0.x.x but it will probably work as long as Firefox maintains the current plug-in architecture.

Step 1

Download the Adobe Flash Plugin installer as XPI from this Adobe.com link.

Step 2

Since this XPI file is just a ZIP archive, rename the downloaded file such that its extension is changed to .zip (e.g. flashplayer-win.zip).

Step 3

Open Windows Explorer and type %APPDATA% in the address bar. Navigate to Mozilla, and further to Plugins. In case these directories do not exist, create them.

Step 4

Copy flashplayer.xpt and NPSWF32.dll from the archive to the above folder.

Step 5

Restart Mozilla Firefox!