While Microsoft’s official “Media Creation Tool” for Windows 8.1 is no longer directly available from their main site (they now push users toward Windows 10/11), you can still obtain a for creating Windows 8.1 64-bit installation media.
Click . The file will be an .iso file, approximately 4.1 GB to 4.4 GB in size. windows 8.1 download 64 bit media creation tool
\boot (boot files)\efi (for UEFI 64-bit systems)\sources (install.wim or install.esd - the main OS image)\supportsetup.exe