Windows 8.1 adds WIMBoot, 16 GB devices can have 12 GB free with new OS install option

Windows 8.1 Update was released to the public earlier this week, but the new version of Microsoft's latest OS could be installed on tablets that have storage capacities as small as 16 GB. Today, Microsoft announced that it has introduced a new install option for Windows 8.1 called Windows Image Boot, or WIMBoot, that's been made to allow those kinds of products a way to get a full version of the OS while still having room for the installations of apps and other programs.

In a blog post, Microsoft said they dislike the typical way that Windows is installed on a new PC via extracting folders from an image file, WIMBoot keeps all of those files compressed. However, the user of the device sees no difference when they explore their storage in the C: folder.

Microsoft says: 

Effectively, you copy the WIM file into a separate “images” partition (just like you would for a recovery image), then use DISM to create pointer files from the standard C: operating system volume into the WIM file. These pointer files are completely transparent, and Windows knows how to boot the operating system (keeping all the files in the WIM) when configured in this setup.

The end result is that a device with 16 GB of storage will be able to keep 12 GB free under Windows 8.1 with a WIMBoot set-up, compared to just 7 GB of free space in the normal method. Microsoft offers up information on how anyone with the right experience can set up a Windows 8.1 WIMBoot install on their PC. Tablets will be sold in the coming months that will have the OS installed by using the WIMBoot method.

Source: Microsoft | Image via Microsoft

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Mobius Enigma said,
This is NOT an unsupported hack. A Registry change is 'supported', or Microsoft wouldn't have the setting available in the registry for the user to change.
Well ok, might be supported but of course end users won't be rushing to do all this any time soon. What we need is a simple "change app location" option in the OS, and it also needs to be a per-app setting (which this registry edit isn't).

scorpian007 said,

Basic users will never do this. Microsoft need an option to do this via the UI.

I agree they should throw in an option to move this via the UI, but the point was that it was already possible and a lot of users already do this. (With a 32gb tablet, using the SDCard for Apps and Program installs is fairly common.)

Speaking of apps on SD cards, has anyone tried a 128GB microSD yet with any of the Surface models? If it works on the Surface RT/2 and Surface Pro/2 I'm thinking of buying a few.

Edited by Romero, Apr 12 2014, 2:08pm :

Let's wait for performance testing. I'm afraid keeping the files compressed will negatively affect performance. And devices with just 16GB storage aren't going to have much CPU power to begin with.

And will windows updates cause the size to blow up since the WIM is read only?

Perhaps they could occasionally apply a diff to the underlying WIM through a special update via WU. Because yes, the way things look, updates will simply replace the pointers (symbolic links? hardlinks?) with actual files and users will eventually find themselves running out of space after a huge Windows update.

mrp04 said,
Let's wait for performance testing. I'm afraid keeping the files compressed will negatively affect performance. And devices with just 16GB storage aren't going to have much CPU power to begin with.

And will windows updates cause the size to blow up since the WIM is read only?

If anything, depending on the speed of the media, this will be as fast or faster.

WIM's compression options are designed to be extremely fast on 'read', which is all it will be doing unless apply an update.

Go look up WIM performance. Microsoft wouldn't be doing this if the performance was going to be a problem.

This is very, very similar to how Android works, with a read-only system partition and a data partition that more or less works as an overlay. Pretty cool.

Ambroos said,
This is very, very similar to how Android works, with a read-only system partition and a data partition that more or less works as an overlay. Pretty cool.

Except it is quite different. Windows already maintains the read-only system, just because it doesn't sit in its own partition is irrelevant.

Go look up Windows Vista/7/8 system protection, virtualization, etc. Windows is already abstracting the OS files with a virtualized ProgramData folder.

This is a lot of crap to do to set this up. Gonna wait till someone makes an easier way to do this or they make it an option to do it directly from the dvd. What I want to do is install MS office, updates and a few MMO installers and then wimboot this to a SSD and use a standard HDD for the other files.

Mr. Dee said,
This is not for the average user.
I consider myself above average on a lot of things but this is just way too much work for so little benefit. MS documentation has always been piss poor at best. In most cases someone comes up with an easier way to do it on a lot of their technologies. For instance with MDT I pretty much had to use youtube videos, forums(msfn.org) and few other fan sites to handle all the stuff MS documentation does not cover.

Ian William said,
Good to see that newer versions are being built on the foundation introduced by Windows Vista.

It's been there from late 2006, and it's only now that it gets to have a more effective use. Sadly Windows Vista was really overlooked.

I always wondered why they didn't use WIM image like that by default. If anyone explores the wim image it is very easily noticeable that it is same as what we see in our C: drive on fresh install.
Glad this is official now.

Windows 8.x based Windows NT 6.x core, like Vista and Win7.

Win. NT 6.x editions' setup bulk size: 2~3 GB (after setup takes up 10~16 GB in disk)
Win. NT 5.x editions' setup bulk size: 500~600 MB (after setup takes up 1~3 GB in disk)

Which is why no surprise fast spreading of Android.

Mobile OSs incredibly fast spreading. In this case, how much longer survive Windows while built over heavy the cores (NT 6.x)? Windows NT 7.0 shouldn't become more clumsy, more over bulky, more RAM-CPU-Disk usage.

If Microsoft inability to creating a new core of Windows NT, at least NT 5.x core can be re-updating, re-modernizing. Of course, this is a utopia. Both mobile and PC versions of Windows will not be changing anything. MS again will continue make heavier, bulky to next Windows.

pureocean said,
Windows 8.x based Windows NT 6.x core, like Vista and Win7.

Win. NT 6.x editions' setup bulk size: 2~3 GB (after setup takes up 10~16 GB in disk)
Win. NT 5.x editions' setup bulk size: 500~600 MB (after setup takes up 1~3 GB in disk)

Which is why no surprise fast spreading of Android.

Mobile OSs incredibly fast spreading. In this case, how much longer survive Windows while built over heavy the cores (NT 6.x)? Windows NT 7.0 shouldn't become more clumsy, more over bulky, more RAM-CPU-Disk usage.

If Microsoft inability to creating a new core of Windows NT, at least NT 5.x core can be re-updating, re-modernizing. Of course, this is a utopia. Both mobile and PC versions of Windows will not be changing anything. MS again will continue make heavier, bulky to next Windows.

Ok, going to stop you. You are mistaken on so many levels, I don't even know where to begin.

A few examples:

The NT 5.x editions didn't install the complete OS and additionally install the source media. This is why there is a big jump between NT 6.x - It also had a ton less drivers that were installed and available at all times. (Go look up the actual binaries, and notice the sizes are about the same.)

As for the 'core', the HAL and NT Kernel (even after merging the SMP HALs) are tiny. The HAL itself started off around 64kb in 1992 and is around 300kb today.

If you think the Windows footprint is huge, go look at Windows Phone, it is running the full OS. The reason it is 'smaller' is that it doesn't have all the extra optional features and drivers.

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