
Information
The most boring part of computing is waiting operating system to be installed. Installing Windows 10 can take anything from 10 to over 30 minutes (depending on hardware). The low end i5 laptop I am using to write this tutorial with an HDD instead of SSD takes on average of 35 minutes from booting with install USB flash drive to OOBE to start with region selection dialog after last restart required by setup, additional 3 to 4 minutes to get initial user created and wait Windows preparing user profile and getting to desktop.
Of course on state of the art hardware, especially using SSD instead of HDD the time needed to install is only about a third of what I need with this hardware.
Whatever hardware you have, applying Windows install image with
DISM (Deployment Image Servicing and Management tool) instead of traditional clean install will significantly reduce the time needed to install Windows. Especially when installing using a customized and personalized Windows image with pre-installed software (see
tutorial) you can reduce the time by up to over 50% but even when using a standard Windows install media you get Windows installed at least over 20% faster.
You can use any valid Windows 10 install media, be it made from a self made ISO from
Windows Insider or Feature Upgrade (
tutorial), a WIM based original ISO Microsoft has available for Windows Insiders (download link in
tutorial), or an ESD based ISO made with Media Creation Tool (download link in
tutorial).
This tutorial although written for Windows 10 also applies to Windows 7, 8 & 8.1.
Contents
Click links to jump to any part
Part One
Boot & Partitioning
1.1) Boot PC from Windows install media (DVD or USB flash drive), continue as in normal clean install until you get to disk options screen. Skip the product key when asked:
1.2) If disk is unallocated, click
New:
(If hard disk is already partitioned as you wish, jump to step 1.5. If you want to wipe an already partitioned disk select existing partitions one by one, select
Delete, and when done continue from 1.3.)
1.3) Set the preferred size of Windows partition (#1 in screenshot) and click
Apply (#2). If you want to use whole disk for a single Windows partition just accept default value and click
Apply:
1.4) Click OK:
1.5) On
BIOS based machine with
MBR disk setup will now create the required
System Reserved partition (500 MB) using the rest of allocated space for Windows partition.
On
UEFI based machine with
GPT disk the
Recovery partition (450 MB),
EFI System partition (99 MB) and
Microsoft Reserved partition (MSR, 16 MB) will be created, rest of the allocated space being used for Windows partition.
1.6) Select the partition where Windows will be installed (Primary partition) and click
Format.
BIOS / MBR:
UEFI / GPT:
1.7) If you did not allocate whole disk for Windows partition, you can leave rest of the disk now unallocated. When Windows has been installed you can use Disk Management to partition remaining space as you wish.

Tip
If you want to allocate a specific amount of space for Windows partition, add 500 MB on BIOS / MBR systems and 565 MB on UEFI / GPT systems.
Example (MBR):
- You want to have a 150 GB Windows partition on a BIOS / MBR system, you should allocate 154,100 MB
(150 * 1024 MB = 153,600 MB = 150 GB plus 500 MB for System reserved partition)
Example (GPT):
- You want to have a 250 GB Windows partition on a UEFI / GPT system, you should allocate 256,565 MB
(250 * 1024 MB = 256,000 MB = 250 GB plus 450 MB Recovery, 99 MB EFI and 16 MB MSR partitions)
1.8) Setup does not show any message when formatting is done. Only indicator of progress is mouse pointer; when formatting, pointer will be an hourglass icon. When ready normal arrow pointer will be shown. Formatting even big hard disks only takes a few seconds.
1.9) When Windows partition has been formatted close
Disk Options dialog. This takes you back to Windows Setup screen:

Note
Advanced users can of course use DISKPART to partition HDD / SSD instead of steps told above.
Part Two
Apply Windows image
2.1) Back on
Windows Setup screen, press
SHIFT + F10 to open
Command Prompt:
2.2) Type
diskpart
and press
Enter to start Disk Partition Utility (see #1 in screenshot in step 2.5)
2.3) Type
list vol
and press
Enter to see list of volumes / partitions (#2). Note the temporarily assigned drive letters for your newly formatted Windows partition and install media (#3). You recognize Windows partition from its size and install media by its type,
Removable if using USB flash drive or
DVD-ROM if using a DVD install media
2.4) Type
exit
and press
Enter to quit Disk Partition Utility (#4)
2.5) Enter following command to check correct index for your preferred Windows 10 edition replacing highlighted drive ID letter with your actual install media ID (#5). Note the index# for edition you want to install (#6):
WIM based install media (Insider or self made ISO):
dism /Get-WimInfo /WimFile:D:\Sources\install.wim
ESD based install media (ISO made using Media Creation Tool):
dism /Get-WimInfo /WimFile:D:\Sources\install.esd
2.6) In this example case now the temporary drive ID for partition where I want Windows to be installed is
G:, Windows install media (USB drive) is
D:, and as I want to install Windows 10 PRO the index# is
1. That's all information I need to apply Windows image (install.wim or install.esd file from Sources folder on install media).
2.7) Enter following command, replacing drive ID letters and Windows edition index# with your actual ones (#1 in screenshot in step 2.9):
dism /Apply-Image /ImageFile:D:\Sources\install.wim /index:1 /ApplyDir:G:\
- ImageFile = Path to install.wim file on install media (install.esd file on media created with Media Creation Tool)
- ApplyDir = temporary drive ID for partition where Windows will be installed followed by :\
2.8) DISM will now apply Windows image to selected partition (G: in this example). This partition will get the correct drive ID
C: when image has been applied and Windows restarted. When DISM is ready you can check that Windows system folders have been created with
DIR G:
command (#2)
2.9) Only one thing missing: we need to create boot records with
BCDBOOT command. We can find it on newly created Windows partition, in Windows\System32 folder. Enter following command to write boot records to make hard disk bootable (#3):
G:\Windows\System32\bcdboot G:\Windows

3.1) Close
Command Prompt, close
Windows Setup:
3.2) Setup thinks now you want to cancel installation, not knowing that Windows has already been installed

. Just click
Yes to let PC restart:
3.3) Windows will now restart booting from hard disk entering the final phase of setup,
Windows Welcome (OOBE) Mode. Select your region, add initial user profile and you are done
That's it!
Kari