So I got the 64bit Win 7 Pro disc from the Ultimate steal for cheap enough... but I found out that some stuff that I want to run (games mostly... since that is the only reason I keep Windows around...) did not do too well on the 64bit OS. So I have borrowed my friend's install disc, but it turns out that his is only Home Premium rather than Pro which I have a serial for.

Can I still just run through the Home Premium install and use my Pro serial number (seems like I should be able to with the whole 'any time upgrade' deal)? Or do I have to go and find a 32bit pro disc to do the install? Are there any hoops that I have to jump through?

  • I would just use my 32bit disc, but the Ultimate steal doesn't ship both discs... you get a choice, 32bit or 64bit discs – SeanJA Jun 10 '10 at 1:52
  • You may be able to download a 32-bit ISO from them. When I got Windows 7 through the ultimate steal, I didn't even purchase media, I just got the download. – nhinkle Jun 10 '10 at 3:00

If you download a Windows 7 Professional 32-bit ISO and burn it to a disc (which does not violate Microsoft's license agreement as you paid for a license), you will be able to use your 64-bit serial number to install and activate it with no problems.

| improve this answer | |
  • I would rather not download a torrented version of the disc for my OS, but if this is the only solution... sigh – SeanJA Jun 10 '10 at 2:03
  • 2
    @Sean I know, I said the same thing. But as long as it's an unmodified, direct-from-disc version, it will be OK. (I believe Microsoft publishes ISO checksums on TechNet or MSDN somewhere; I'd check it just to be sure). It's a pain, but you have to do it sometimes. – squircle Jun 10 '10 at 2:07
  • Do you know of any self installers, rather than burning a dvd? The ultimate steal had one, but it had some flaws that were causing it to crash when you tried to run it. – SeanJA Jun 10 '10 at 2:07
  • @Sean You'd have to extract the ISO to a USB drive, external hard drive, burn it to physical media or run the install over the network. There's no local installer that can fully complete a Windows installation, unless you go through the hassle of making a new partition and putting the install files on it... which is more of a pain than it is useful. – squircle Jun 10 '10 at 2:09
  • I guess I go to the store tomorrow to pick up a pack of dvds then... – SeanJA Jun 10 '10 at 2:14

You can use win7utils to achieve this.

win7utils - Windows 7 ISO Disc Image Utilities

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 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).

Alternatively, you can do it the manual way by following these instructions, which tell you how to modify the ei.cfg file to change the edition.

| improve this answer | |
  • Essentially the same thing as what I posted, but with easier instructions. +1 – nhinkle Jun 10 '10 at 16:32

There is a way using your friend's media, meaning you won't have to download a torrent. It will require that you burn a new disk though.

  • Copy everything from the disk into a folder on your computer.
  • Delete \sources\ei.cfg
  • Build a new bootable DVD with the source you just copied
    • You can do this with ImgBurn; you'll have to figure out the options for creating a bootable CD. If you have trouble with it, comment and I'll try to add more details.
    • You could also consider installing from a flash drive, so you don't have to waste a DVD and deal with trying to burn an image. These instructions have worked for me before.
  • The new disk will give you the option at install time to choose which version of Windows 7 to install (Home Premium/Pro/Ultimate). Make sure of course to select the right version for your product key.
| improve this answer | |
  • Will this install windows home premium with his ultimate product key? Based on the online reading... it sounds like it'll install ultimate edition windows with a home premium cd. – James T Jun 10 '10 at 3:11
  • No. It will install whichever version he chooses when he goes to install. Presumably, he will choose to install Windows 7 Professional, since that's what his key is for. The DVD will no longer be a home premium disk, it will be a generic disk, and will let him choose what to install. – nhinkle Jun 10 '10 at 3:16
  • Won't copying everything from the disk to a folder on his computer (in the traditional copy-paste way) result in the loss of the boot information present in the Windows disc? I would recommend using apps like PowerISO, MagicISO or UltraISO to remove the ei.cfg file from the image. – Om Nom Nom Jun 10 '10 at 8:23
  • It will lose the boot information, yes, which is why when he rebuilds the disk using imgburn he must select the option to make it bootable. Another way would be to use imgburn to create an image, then open the iso in 7-zip, delete the ef.cfg file, then save the modified iso, and re-burn that. – nhinkle Jun 10 '10 at 16:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.