Windows 8 boots really faster than its predecessors, and the main reason behind that is the newly implemented ‘hybrid boot’ or ‘fast start-up’ feature. As the name suggests, it is nothing but an improved version of the existing ‘hibernate’ feature that had been there in Windows operating systems for a long time.
Below is a simple explanation of the process and few ways that you can use to disable this feature …
An operating system’s boot process can be divided into two main ‘phases’ called he ‘Kernel Session’ and the ‘User Session’. The ‘Kernel’ is the heart of an operating system because it is what that communicates directly with your computer’s hardware, and act as the ‘middleman’ between hardware and applications that run on top of your desktop.
So when an OS boots, after a bit of a help from BIOS and other tools, it loads the ‘Kernel’ into the RAM first. Then the ‘Kernel’ calls in drivers of your hardware, then other core system services (such as network related services), and then it prepares the user’s login window by executing programs that are responsible for that (such as the display or the ‘login manager’).
Most of it is done in a sequential order, some can also be executed parallel too. And because these programs run ‘closely’ with the ‘Kernel’, before logging in the user (above users privileges), some call it the ‘Kernel Session’.
At the end of the ‘Kernel Session’, the user should be presented with his/her usual graphical login screen. And from then, the desktop and the applications that are set to run with it will be loaded. And at the end the user should have a fully workable desktop.
So from the moment the user enters his/her login details, till the desktop fully loads, because those programs are executed through that user’s privileges, this session is known as the ‘User Session’.
Shutting down is also the same, but it is executed in a reverse order. First the ‘User Session’ is terminated and then the ‘Kernel Session’. Once that is done, the OS notifies the BIOS and it shutdown the computer.
How ‘hibernation’ helps?
The ‘Kernel’ has the ability to ‘Suspend’ and ‘Resume’ programs. And when an active program is ‘suspended’, it goes into a sleep mode. And when it is resumed, it will start to function from the previously suspended state, as of nothing has happened!.
For example, while playing a video in Windows media player, if I suspended it, then the player will look like it is stuck and the playback will be paused.
But this is very different from ‘pausing’ the video, though ‘suspending’ too pauses the playback, the media player will also stop functioning completely. But the thing is, if you ‘Resume’ it later, then the video playback will continue from where it was suspended, as nothing happened, and you’ll be able to use it as usual (this whole time its data will be kept in RAM).
‘Hibernation’ actually goes another step forward. Not only it suspends applications, but rather than keeping them in the RAM, it also saves that data (exactly it is) into the hard disk drive. And due to few reasons, restoring a suspended application from disk to the RAM, is faster than re-opening it from scratch.
Because of that, when you hibernates an operating system, what earlier versions of Windows did was, it suspended all the running applications in the ‘User Session’, and then it did the same to apps that were executed in the ‘Kernel Session’. And then the OS saved all of their data on the RAM into a file on your hard disk (called ‘hiberfile.sys’) and then it turned off the computer.
Because the ‘hiberfile.sys’ is sort of like a ‘snapshot image’ (a special kind of a backup file), next time you turn ON the computer, the OS can restore the saved data much quicker. Plus, it also won’t have to worry about programs and their loading sequences etc (that otherwise slowdown the process) because unlike opening programs from ‘scratch’, for ‘suspended’ programs that are restored using the ‘hiberfile.sys’ file, that is already being done (such as saving and restoring them into their last saved ‘sessions’ etc).
So all in all, the OS can just load all the data of the ‘hiberfile.sys’ into the RAM and resume the programs from there, and it significantly reduces the boot times.
However, the ‘User Session’ can easily become the bottleneck of this process. That is because, unlike with the ‘Kernel Session’, because applications that run on desktop (‘User Session’) can consume a lot of memory (RAM), and the ‘hiberfile.sys’ could easily become large.
Because copying a large file from hard disk to the RAM (say more than a Gigabyte) can take a lot of time, therefore, a hibernated computer, though in theory should boot faster, in those situations, can instead boot slower than usual!.
So to overcome this, when shutting down, Windows 8 only hibernates the ‘Kernel Session’ and carries out the termination of the ‘User Session’ as usual (without saving it to disk), and this significantly improved the boot times as it reduces the overall size of the ‘hiberfile.sys’ (by a lot).
If you have a multi-core processor, then Windows 8 also has the ability to use all the available cores for this executing this process for further speeding things up as well.
Why you need to worry about a ‘full boot’ then ?
When an OS boots, prior to loading the device drivers, the ‘Kernel’ also checks for new hardware that might have been added after its previous shutdown. If it finds one, then it’ll take the necessary action (installing device drivers automatically or notifying the user etc).
In Windows versions prior to 8, in ‘hibernate mode’ the OSs did not check for the drivers. Therefore, if you had added a new hardware after hibernating, then upon the next OS boot, they might not be ‘detected’, and it was one of the main drawbacks of hibernation.
But here is what ‘Steven Sinofsky’, a Microsoft employee says about Windows 8 …
Another important thing to note about Windows 8’s fast startup mode is that, while we don’t do a full “Plug & Play” enumeration of all drivers, we still do initialize drivers in this mode.
Those of you who like to cold boot in order to “freshen up” drivers and devices will be glad to know that is still effective in this new mode, even if not an identical process to a cold boot.
So it seems that if the reason wanted to disable ‘hybrid boot’ was because this reason, then it might not be necessary at all. However, once in a while, to freshen up the OS, if you want to perform a normal (‘full’) boot nevertheless, then you can follow one of the below methods.
Without doing any of below methods, you can also select ‘Reboot’ from the ‘Power’ button, as it perform a ‘full boot’ by disabling ‘hybrid boot’ temporarily. But that of course will restart the computer rather than shutting it down.
Temporarily disabling it …
1. Because ‘hybrid boot’ makes your computer boots fast that you have decided to keep it but only wanted to temporarily disable it, then the most easiest way of doing that is to press down and hold the ‘Shift’ key while clicking on the ‘Shut down’ menu item.
2. You can also achieve the same thing by pressing the ‘Windows key’ + ‘R’ and then put the below command in the command box and click on the ‘OK’ button.
Permanently disabling it …
Whenever you hit the ‘Shut down’, if you want Window 8 to shutdown it fully as usual, therefore permanently disabling this feature and making a ‘full boot’ (also known as ‘cold boot’) every time your turn the computer ON, then please follow the below procedure.
Open ‘Control Panel’ and search for the below term.
change what power buttons do
This should open the ‘Power Options’ icon and then click on the link below it called ‘Change what the power buttons do’ to open the configuration page.
Now, at the top of this page, if you can see a blue text link called ‘Change settings that are currently unavailable’ (shown below), then click on it first, otherwise you won’t be able to change those settings.
Then simply scroll down and under the sub-heading ‘Shutdown settings’, remove the check mark of the option called ‘Turn on fast start-up (recommended)‘. Then click on the ‘Save changes’ button below to close the window and apply the changes.
Well, that’s it, now you should have permanently disabled ‘hybrid boot’ in Windows 8.
Note: You can always come back to this page and put a check mark on the ‘Turn on fast start-up …’ option to re-enable it. Good luck.