Update: Instructions for IE 7 beta 2

IE7 on Windows 2003, and they said it couldnt be done ;) First the picture.

I think we will follow my path installing this to help understand how I reached the conclusions I did. I first tried to install IE 7 and got the unsupported operating system issue. I used WinRar to unpack the install into a folder.

Looking in the update folder, we see the magic file that is keeping us from installing, the update.inf file. The top of the file looks like this.

[Version]
    CatalogFile               = %SP_SHORT_TITLE%.cat
    LanguageType              = %LangTypeValue%
    MaxNtBuildToUpdate        = 9999
    MaxNtMajorVersionToUpdate = 5
    MaxNtMinorVersionToUpdate = 1
    MaxNtServicePackVersion   = 512
    MinNtServicePackVersion   = 512
    NtBuildToUpdate           = 2600
    NtMajorVersionToUpdate    = 5
    NtMinorVersionToUpdate    = 1
    RebootRequired            = 1
    Signature                 = "$Windows NT$"

This basically tells the installer that the service pack has to be SP2 (the minntservicepackversion of 512) and the OS has to be XP (the maxntminorversion of 1).

Before you touch this file, make a backup on your desktop, somewhere you can get to it quickly. No this isnt the normal 'we may break it so we want a backup', anyone who knows me knows I wouldnt make a backup for that reason. You will see why in a moment.

Now in the inf that is still in the update folder, change that section to read as follows.

[Version]
    CatalogFile               = %SP_SHORT_TITLE%.cat
    LanguageType              = %LangTypeValue%
    MaxNtBuildToUpdate        = 9999
    MaxNtMajorVersionToUpdate = 5
    MaxNtMinorVersionToUpdate = 3
    MaxNtServicePackVersion   = 512
    MinNtServicePackVersion   = 0
    NtBuildToUpdate           = 2600
    NtMajorVersionToUpdate    = 5
    NtMinorVersionToUpdate    = 1
    RebootRequired            = 1
    Signature                 = "$Windows NT$"

Here we are allowing for minor version up to 3 (windows 2003 server) and no service pack level. This may also allow you to install on XP without a service pack, and this might let the installer run on Windows 2000 as well with changes to the minor version, though I would doubt either of these working. I seem to recall IE 7 in its current build uses code inherent to the Windows XP2 (Windows 2003 sp1) builds. I havent tested either so have at it if you wish.

For those that said WOOHOO! and went ahead and ran the install, you are probably disappointed. There is a security catalog in the same directory that has a hash of the inf file and this fails to validate the modified inf and setup fails. As I experimented, I noticed that the cryptography failure didnt show up at a consist point or time period, so it would seem it is spinning off on its own thread. Here in lies the solution.

Remember that backup I had you make? Launch the installer, and immediately upon it rendering, grab the backup inf and drop it back into the update folder. Answer yes when it asks you to overwrite the file. If you were expediant, you will have replaced the original inf before the crypto call has checked its authenticity and setup will continue. You will get an error that a Windows XP SP 2 specific registry key (my guess anyhow) can not be found. Fortunantly you have the option to ignore it.

Setup completes as normal and requires a reboot. Reboot and you now have IE7. Thanks for the fun steveb, but try alittle harder next time ;)