As we have discussed many times before, the private browsing mode in Firefox allows you to surf the internet without leaving any fingerprints. Other browsers call it incognito mode and it prevents your web browsing history from being saved to the local disk. Typically, you start the private browsing mode in Firefox either through the Firefox menubar or using a hotkey. But if you have a reason to disable the private browsing mode in your PC (perhaps because your friends are surfing objectionable websites behind your back in the private browsing mode), then you can use the Disable Private Browsing extension to do that.
Disable Private Browsing extension for Firefox does not really block anything – you can still launch the private browsing mode through the menubar File → New Private Window or through the hotkey Ctrl+Shift+P. The only thing this extension does is adds an alert message whenever you open a private browsing window. If you close the alert message, the private window closes down. And you cannot really use the web browser with an alert message being shown.
One another trick that Disable Private Browsing extension uses is that it blocks removal of this add-on from Firefox. But you can always re-launch the Firefox browsing in the safe mode and then remove this extension. In order to launch Firefox in the safe mode, type about:support in the address bar, press Enter and then click on Restart with add-ons disabled button. Then you can open the add-ons page by typing about:addons in the address bar and then remove this add-on.
Disable Private Browsing extension for Firefox can be used to disable the private browsing mode (also called the incognito mode). This can be a deterrent for the less tech-savvy users, but others can quickly remove this extension and still manage to use the incognito mode.
You can download and install the Firefox web browser from https://addons.mozilla.org/en-US/firefox/addon/disable-private-browsing/.