When you try to install Windows 11 via a bootable USB flash drive, you might unexpectedly see this dialog:
More often than not, this dialog is misleading: While there are rare cases when Windows PE indeed requires additional drivers to access the disk drives in your computer, it is more likely that there is simply an issue with your USB flash drive.
To verify this, press Shift+F10 to open a console window and type notepad X:\$WINDOWS.~BT\Sources\Panther\setupact.log to inspect the log file. Windows Setup searches for a install.wim, install.esd or install.swm file, and under normal circumstances, it will locate that image file on the USB flash drive – drive D:\ in this example:
2026-07-27 16:19:28, Info MOUPG Driver: Searching for install images...
2026-07-27 16:19:28, Info MOUPG Driver: Module to hash is [X:\Sources\SetupHost.exe]
2026-07-27 16:19:28, Info MOUPG Driver: Evaluating drive [D] as media location
2026-07-27 16:19:28, Info MOUPG Driver: Media located at drive [D]
2026-07-27 16:19:28, Info MOUPG Driver: Found install image at [D:\Sources\Install.wim]
2026-07-27 16:19:28, Info MOUPG Driver: Found Media path at [D:]However, when the USB flash drive is unreliable, Windows Setup might be able to boot from it, but then fail to locate the image file:
2026-07-27 16:19:28, Info MOUPG Driver: Searching for install images...
2026-07-27 16:19:28, Info MOUPG Driver: Module to hash is [X:\Sources\SetupHost.exe]
2026-07-27 16:19:28, Info MOUPG Driver: Evaluating drive [D] as media location
2026-07-27 16:19:28, Info MOUPG Driver: Drive [D] did not contain [D:\Sources\SetupHost.exe] at expected location
2026-07-27 16:19:28, Info MOUPG Driver: Found install image at [(null)]
2026-07-27 16:19:28, Info MOUPG Driver: Found Media path at [(null)]
2026-07-27 16:19:28, Warning MOUPG Unable to find mediaLoading whatever driver will not fix that. Instead, try these steps to remedy the issue:
pnputil.exe /enum-devices /problem to see which devices Windows did not recognize.