http://code.kliu.org/misc/win7utils/
Local cache:
http://justinho.com/files/uploads/eicfg_removal_utility.zip
http://justinho.com/files/uploads/windows7_iso_image_edition_switcher.zip
ei.cfg Removal Utility
Version 1.1
The ei.cfg Removal Utility is a simple tool that will remove the ei.cfg from any Windows 7 ISO disc image, thereby converting the image into a "universal disc" that will prompt the user to select an edition during setup. This tool works by toggling the deletion bit in the UDF file table, eliminating the need for unpacking and rebuilding the ISO, which means that this is extremely fast (the process of patching the ISO to remove ei.cfg takes only a fraction of a second), and the process is easily reversible (running the utility on a disc image patched by this utility will restore the disc image to its original state).
Windows 7 ISO Image Edition Switcher
Version 1.0
The Windows 7 ISO Image Edition Switcher is a set of small binary patches (and a tool to apply these patches) that will convert an official Windows 7 ISO disc image into an official Windows 7 ISO disc image of another edition. 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.
The patches and patcher in this package can be used to convert any 32-bit image
into another 32-bit image and any 64-bit image into another 64-bit image.
For example, if you downloaded the 32-bit Ultimate ISO disc image from MSDN and
you also want a 32-bit Professional image, instead of spending another 2.3 GB of
bandwidth, you can make a copy of your Ultimate image and then patch that into a
Professional ISO disc image; the result should be exactly identical to what you
would have gotten had you downloaded the ISO image separately.
1) Run binpatch.exe
2) Select the the patch for the target edition that you want
3) Select the ISO disc image that you want to convert from
4) After patching, you should verify the SHA-1 hash of the final file and
compare that with Microsoft's official hash to verify that the patch was
successfully completed.