Official Microsoft ISO downloads

Choose Windows media that matches your edition and licence

Before creating installation media, open Settings > System > About and record the Windows edition and system type. Check Settings > System > Activation separately to confirm activation status. A Home licence does not activate Pro, and changing between x64 and Arm64 requires hardware-compatible media, not merely a different key. For a reinstall on the same device, the same edition will usually reactivate automatically online if that device already has a matching digital licence.

A successful activation does not establish that a licence was purchased or transferred lawfully. Microsoft's Windows terms distinguish software preinstalled on a device from software acquired separately: preinstalled rights generally transfer only with the licensed device, while standalone software may be moved subject to the applicable terms and removal from the previous device. Linking a Microsoft account can help with reactivation after hardware changes, but it does not turn an OEM licence into a transferable retail licence.

• Record the installed edition and activation status before erasing the drive.
• For a matching digital-licence reinstall, select “I don't have a product key” if prompted.
• Firmware-embedded keys can cause Setup to select an edition automatically.
• An organisation's volume activation may require its network or activation infrastructure.
• Check the Microsoft Software License Terms supplied with your specific licence before transferring it.

Prepare recovery options before running Windows Setup

Decide whether you need an in-place reinstall or a clean installation before starting Setup. To preserve supported combinations of apps, files and settings, start setup.exe from compatible installation media while signed into the existing Windows installation. Booting from USB follows a different installation path and does not preserve installed applications. Availability of the keep options depends on factors such as edition, language, architecture and version; stop if Setup offers fewer preservation options than you expected.

Create a separate backup of important files and verify that you can open it before changing partitions. Save your BitLocker or Device Encryption recovery key somewhere accessible without the PC, because firmware or boot changes can trigger recovery. If Microsoft provides a SHA-256 value for the exact ISO, calculate the downloaded file's hash and compare every character. A matching filename, familiar download page or valid-looking product key does not verify the contents of an installation image.

• Calculate an ISO hash in PowerShell with Get-FileHash -Algorithm SHA256 -Path "C:\Downloads\Windows.iso".
• Compare against the exact release, language and architecture Microsoft identifies.
• Back up the USB drive first; media-creation tools can erase its contents.
• Keep storage-controller and network drivers available for the target hardware.
• If Setup cannot see the intended disk, investigate drivers and firmware settings before deleting partitions.

Install the correct Office product with the Deployment Tool

The Office Deployment Tool is an installer and configuration utility, not a licence or a universal Office package. Extract it into a working folder and create a configuration XML using Microsoft's documented product identifiers, channels and architecture options. Run setup.exe /download configuration.xml to obtain the specified files, then setup.exe /configure configuration.xml to install them. The download stage is optional when installing directly from Microsoft's content delivery network, but useful when preparing an offline deployment or staging installation files locally.

Match the configuration to the entitlement you actually hold. Office LTSC volume editions, retail perpetual editions and Microsoft 365 subscriptions are not interchangeable merely because their applications look similar. A volume installation can require MAK or KMS activation rather than a retail account-based process. On a Mac, the Deployment Tool does not apply: use the appropriate Mac installer and activation method. Installing a current package does not grant a subscription or unlock features outside the licensed product.

• Use Microsoft's Office Customization Tool where appropriate, then review the exported XML.
• Run installation commands from the folder containing setup.exe and the XML file.
• Do not mix 32-bit and 64-bit Office products on the same Windows installation.
• Check Microsoft's coexistence guidance before combining Office, Project and Visio releases.
• Back up Outlook data and document customisations before removing an existing Office installation.

Treat Server evaluation and SQL Developer as restricted-use downloads

Windows Server evaluation media is intended for evaluation, not as a substitute for a production licence. Before attempting conversion, run DISM /online /Get-CurrentEdition and DISM /online /Get-TargetEditions from an elevated terminal. The supported targets determine whether an in-place edition conversion is available; a purchased key alone cannot make an unsupported path work. For a supported evaluation conversion, Microsoft's documented DISM procedure specifies the target edition, a suitable product key and acceptance of the licence terms, followed by a restart.

SQL Server Developer includes Enterprise functionality but is licensed for development and testing, not production workloads. A live business database needs an appropriately licensed production edition, or Express if its feature and capacity limits are suitable. Windows Server and SQL Server licensing must be assessed separately: licensing the operating system does not license the database engine. Depending on the deployment and licensing model, core licences, server licences and client access licences may be relevant; activation alone does not settle these obligations.

• Windows Server evaluation normally has a 180-day evaluation period; check the installed evaluation status.
• An evaluation domain controller cannot be converted directly to a retail installation; follow Microsoft's migration guidance.
• Do not assume an evaluation Datacenter installation can convert to Standard.
• Back up servers and databases before edition conversion or upgrade work.
• Check SQL Server's supported edition-upgrade paths before attempting Developer-to-production conversion.

What each download provides—and what you must check separately