I am not exactly sure quite what you are asking, so could you provide some more information to clarify.

It seems that you may be restarting your machine from Hibernate, so everything that was running comes back as it was, including the minimized Firefox on the taskbar, is that correct?

I believe that when Firefox is minimized, everything is still running as normal, you are just not looking at it. If you look at the Firefox processes under Windows Task Manager or Resource Monitor everything is the same and they are changing in the background, regardless of whether Firefox is minimized or not.

Could you please explain what you are trying to achieve (or prevent happening)?

Are you hibernating a machine in one location, then restarting it in another one with entirely different networking?

What operating system are you using and are your running Firefox 57?

yes on firefox 57, yes on disconnecting from one network and activating on a new one.

will the new one see activity from them minimized window

Thank you for your reply.

I just tried a little experiment on one of my desktop PCs running Windows 10 Pro, Firefox 57 and connected to the network via wired Ethernet. I opened Firefox, loaded a number of sites in different tabs (some logged in), shut down the machine with Hibernate, disconnected the Ethernet cable and restarted the machine.

When I bring up Firefox from minimized, all of the sites in all of the tabs are displayed just as they were before the Hibernate. Obviously, if I click a link or try to navigate on a site it fails as there is no Internet connection.

testingapp said

will the new one see activity from them minimized window

I believe that whether your new network sees activity from an open tab or not depends on the web page that is loaded in it and whether or not an automatic refresh request is made (by the web page, or if you if you manually right-click a tab and select "Reload Tab", etc.). If the web page is "static" and was completely loaded prior to you doing your hibernate, then there is no reason why there should be any traffic to or from that page. There are extensions that can be set to automatically reload tabs every x amount of time passed too (but if you had one like that installed I am sure you would know about it).

I am not an expert on this, so one of the other contributors might give you more definitive information.

I am wondering about your motivation. Are you trying to hibernate a laptop at home with a website displayed that you would like to show someone at work and do not want your work network to detect that you have that page loaded on your laptop? If so, you might be in dangerous territory if that site is normally blocked on your work network. If it is a work laptop, rather than your own, it is highly likely that your IT department is able to monitor anything you are doing with it, should they wish to.

Does that answer your question?