: Third-party security software flag and lock winsetup.dll during an in-place upgrade.
If the media is new and the BIOS is correct, the computer may be losing connection with the hard drive or the installation media during the file copy process.
The USB stick itself is failing, or the USB port is not supplying consistent data. how to fix windows could not load required file winsetup.dll
: Hardware defects in the USB drive itself can cause read errors for specific DLLs. 2. Run System File Repairs
This article provides a comprehensive guide to resolving the error, which typically occurs during a clean installation or upgrade of Windows 10 or 11. : Third-party security software flag and lock winsetup
If you have an existing Windows installation (even if it won’t boot), you can use DISM to fix the corrupted Windows image that contains WinSetup.dll.
Try running the Windows installation. If it fails, swap that stick for the other one. : Hardware defects in the USB drive itself
You may have a broken bootloader. A previous failed installation left references to WinSetup.dll in the Boot Configuration Data (BCD). Run bootrec /fixboot and bootrec /rebuildbcd from recovery.
In over 80% of cases, this error is caused by a corrupted USB flash drive or a poorly flashed ISO file.