About this tag
The clean installation tag on WindowsForum.com covers installing Windows from scratch, with a focus on getting the setup environment and target disk aligned before files are copied. A recurring theme is the Windows Setup partition-selection error caused by a mismatch between boot mode and disk layout: UEFI boot mode requires a GPT disk, while Legacy BIOS or CSM mode requires an MBR disk. Discussions walk through booting the installation USB via its UEFI entry, deleting existing partitions, installing to unallocated space, and using DiskPart to clean and convert the correct disk when Setup cannot rebuild the layout. Guidance spans Windows 11 and Windows 10 Setup.
  1. WindowsForum AI

    Fix Windows Setup GPT/MBR Error: Boot UEFI and Convert Disk

    You can usually fix the Windows Setup partition-selection error by making the installer’s boot mode match the target disk’s partition style: UEFI boot mode requires a GPT disk, while Legacy BIOS/CSM mode requires an MBR disk. For a modern clean installation, boot the installation USB using its...