Windows 10 will use several gigabytes less disk space than its predecessor, in a move that will be particularly welcomed by owners of Windows tablets. Microsoft is making the disk space savings by making better use of file compression and by removing the recovery partition.
Microsoft says it can shave around 2.6GB off the installation space required for exisiting 64-bit builds of Windows 10 by compressing the system files. However, the company admits that not all Windows 10 devices will have the necessary grunt cope with decompressing system files.
The company says the operating system will decide whether a particular device can cope during the installation procedure. "One important factor is the amount of memory (RAM) a device has,"Microsoft states in a blog explaining the changes. "The amount of RAM a device has determines how often it retrieves system files from storage. Another important factor is how quickly a device’s CPUs can run the decompression algorithm when retrieving system files. By considering these and other important factors, Windows is able to assess if a device can use compression without reducing human-perceivable responsiveness."
It's not only the operating system that Microsoft plans to compress, but apps installed from the Windows Store. "When compression makes sense for a device’s system files, it also makes sense for its apps," says Microsoft. "Because of compression, you will have more spare capacity for store apps and the store apps themselves will use less capacity." Microsoft doesn't give any indication of how much space might be saved by compressing a typical app, but given that individual games can now consumer a gigabyte or more of storage, any saving will be welcomed by those running devices with as little as 16GB of base storage.
Recovery wiped
More controversially, Microsoft is also doing away with the recovery partitions that have become a mainstay of PC installations since manufacturers stopped supplying recovery discs with new machines. Microsoft says it's now possible to recover Windows without duplicating the system files.
"Without a separate recovery image, the Refresh and Reset functionalities will instead rebuild the operating system in place using runtime system files," Microsoft claims. "Not only does this take up less disk space, it also means you will not have a lengthy list of operating system updates to reinstall after recovering your device."
However, the onus will seemingly shift to users to create their own recovery media - normally in the form of a bootable USB drive - should the primary system files become overwritten or damaged beyond repair. "Even though Windows no longer requires a separate recovery image, Windows can still recover a device from severe corruption," Microsoft insists. "With Windows 10, you can create your own recovery media and back up the pristine state of the operating system and preinstalled software. If things go wrong and you are unable to refresh or reset your device successfully, you can boot the device using recovery media and reset to the prior pristine stat."
Total savings
The combined savings generated by compressing the system files and removing the recovery image will amount to around 6.6GB of freed storage space, when compared to Windows 8.1, Microsoft claims. The space savings could be even greater on systems that incorporate lots of pre-bundled applications from the PC vendor into the recovery partition.
The returned disk space will be of most benefit to those running compact tablets with as little as 16GB of storage, although Microsoft cautions that it's not yet possible to upgrade these devices to Windows 10, as they don't have enough free disk space to handle the installation files. The company says it is "evaluating a couple of options for a safe and reliable upgrade path for those devices".