Buy Windows Installation Disc -

: A common source for OEM install DVDs and brand-specific reinstallation discs (e.g., Dell or HP).

To obtain a Windows installation disc, you can either purchase a physical retail copy from authorized retailers or create your own for free using official Microsoft tools. buy windows installation disc

Creating your own media is often faster and ensures you have the latest version of Windows. Create installation media for Windows - Microsoft Support : A common source for OEM install DVDs