How to make a Windows 7 "universal disk"

From the ISO file of Windows 7 Ultimate, any language, x86 or x64, you can make a "universal disk" that will prompt you to select which version to install (Home, Pro, etc.).

Use the excellent ei.cfg Removal Utility to edit your ISO file.

From the site: "The resulting ISO images are bit-for-bit identical with those posted on MSDN or TechNet, and their SHA-1 hashes should match the official hashes posted by Microsoft. This tool works by toggling the deletion bit in the UDF file table, eliminating the need for unpacking and rebuilding the ISO."