It's probably another program causing your problems.
Firefox displays 'not responding' when something else is hogging all of you computer's memory (and/or its CPU). The usual culprits are security programs or Windows itself installing updates. In particular, Windows own security software (Microsoft Security Essentials or Windows Defender) has a nasty habit of hogging all of a computer's resources during the update process, leaving nothing for other programs (such as Firefox) to work with.
So perhaps you need to consider switching to a different security solution?
Try the following:
When you first switch your laptop on, launch the Task Manager (via right-clicking on your task bar). You need to do it before any problem occurs because you won't be able to launch the Task Manager if something is hogging all of your laptop's resources later on.
Click on the Processes tab and then on the Memory column heading; you'll then have all running processes listed so that those using the most memory are at the top of the list.
Then minimise the Task Manager down to the task bar.
When you next encounter a 'not responding' message from Firefox, click to bring the Task Manager back onto your screen again.
I'd be prepared to be that 'svchost.exe' has now jumped to the top of the list, showing a massive amount of memory usage. If I'm correct then it's definitely something other than Firefox which is causing the problem (while using svchost.exe to download and install an update).
You then need to try to work out exactly which program is making the call on svchost.exe. Look down the 'Memory' column for a figure which keeps changing every second or two; that will probably be the real cause of the problem. If the frequently-changing memory figure appears alongside 'trustedinstaller.exe' then it's a Windows update. Other well-known cause are MsMpEng.exe (which is part of Microsoft Security Essentials) and occasionally AvastSvc.exe (which is part of Avast). If you don't recognise the name of the offending process simply google it.
Once you know which program is the real cause of your problem you'll be in a better position to move forward. (I largely solved the problem on my own computers when I got rid of Microsoft Security Essentials and installed Avast instead).