Using a tool like is the standard method for making the ISO bootable. Hiren's BootCD PE
If you specifically need a 32-bit bootable environment for older hardware, here are your best options: : The most popular 32-bit version. Includes Mini Windows XP for a familiar GUI on old systems. Contains DOS-based tools for BIOS-level repairs. Available on the official Old Versions page . Unofficial PE Builds : Some community members create custom WinPE 32-bit ISOs. Hbcd-pe-x32.iso