英文原文如下,大致的意思就是删除下面四个文件即可：

Filefox安装目录\plugins\npmozax.dll

Filefox安装目录\components\nsIMozAxPlugin.xpt

Filefox安装目录\components\nsAxSecurityPolicy.js

Filefox安装目录\defaults\pref\activex.js

以下为原文：

Uninstalling ActiveX

Should you want to uninstall AxtiveX, the process is simple - only four files need to be manually deleted from the Firefox program folder.

Step 1. Go to the Firefox program folder (the location you installed Firefox to). The default location in Windows is 'C:\Program Files\Mozilla Firefox\'

Step 2. Go into the plugins folder and delete the file 'npmozax.dll'

Step 3. Go back to the Firefox program folder, and then go into the components folder, and delete the files 'nsIMozAxPlugin.xpt' & 'nsAxSecurityPolicy.js'.

Step 4. Go back to the Firefox program folder, and then go into the defaults\pref folder, and delete the file 'activex.js'.