One of the biggest frustrations when installing Windows XP was making sure you had the correct CD for your license key. Windows Vista fixed this problem by having a universal CD that contained all versions (all 32bit versions or all 64bit versions, not both) and simply installed the version that the key matched.
Now that Windows 7 is out, Microsoft have reverted back to needing a separate disk for each version which is annoying for us computer technicians. However, the only difference between each DVD is a small 51 byte configuration file called ei.cfg which tells the installer what version disc it is. If you were to turn your DVD into an ISO, remove this ei.cfg file and write it back to a DVD, that DVD would become a Universal DVD.
ei.cfg Removal Utility will make this easy for you. Just create an ISO with your legitimate Windows 7 DVD, run this tool, choose the ISO and let it run. Once it has finished, just write the ISO back to a DVD again and you would only need to carry one 32bit version and one 64bit version to support any Windows 7 install onsite.
Of course, your client would still need to provide you with a working key for the Windows 7 install to work.
Download from the Coders Site – 4.64kb
Special thanks to our forum member AtYourService for recommending this one.