If you are installing on a physical server, you must turn the ISO into a bootable USB or DVD. Hardware Requirements for Windows Server - Microsoft Learn

| Problem | Likely Cause | Solution | |---------|--------------|----------| | "A media driver your computer needs is missing" | Missing storage driver (NVMe/RAID) | Download the driver to another USB, click , browse to the .inf file. | | Bluescreen after first reboot (INACCESSIBLE_BOOT_DEVICE) | BIOS SATA mode set to RAID instead of AHCI or vice versa. | Change BIOS SATA mode to match your setup. Often requires reinstallation. | | "Windows cannot be installed to this disk (GPT required)" | BIOS booting in legacy CSM mode, but disk is GPT. | Reboot into UEFI mode, or convert disk to MBR using diskpart convert mbr (not recommended). | | USB drive not recognized as bootable | ISO written incorrectly (e.g., as file, not as image). | Re-write using Rufus in DD mode or use dd on Linux. | | Product key rejected | Using an evaluation key on a retail ISO or vice versa. | Click "I don't have a product key" and enter key after installation via Settings > Activation. |