I'm reinstalling Windows 11 from a USB installer after a security incident and want to perform a genuinely clean installation. Windows Setup is showing several partitions and I'm unsure which ones are safe to remove. Which disk and partitions should I select, and what should the drive look like before I continue? I'll back up anything important first, but I want to avoid accidentally wiping the USB installer or another drive.
3 Answers
The USB installer may appear as a separate disk, so identify drives by their size and disk number rather than deleting entries blindly. The target drive should end up showing one block of unallocated space with its full capacity available. If the layout doesn’t match that, stop and double-check before continuing.
A clean install will erase everything on the selected disk, including personal files, recovery partitions, and existing Windows data. Back up important files and verify the backup before proceeding. If more than one internal drive is connected, disconnect any drive you don’t want to risk wiping, then install Windows into the remaining drive’s unallocated space.
If you’re certain which drive is the internal Windows drive, delete every partition listed under that physical disk—often shown as Disk 0—until it displays a single entry labeled Unallocated Space. Then select that unallocated space and click Next. Do not delete anything on the USB installer or on another drive containing files you need.
So I should confirm the disk number and capacity first, then remove only the partitions belonging to the internal Windows drive?