In another interesting twist, those who choose to install SP3 for Microsoft Windows XP, will lose the ability to downgrade from IE7 to version 6. On a recent blog entry by a Microsoft developer, this fact and others were confirmed. The article also states:

Internet Explorer 6 Users

XPSP3 will continue to ship with IE6 and contains a roll-up of the latest security updates for IE6. If you are still running Internet Explorer 6, then XPSP3 will be offered to you via Windows Update as a high priority update. You can safely install XPSP3 and will have an updated version of IE6 with all your personal preferences, such as home pages and favorites, still intact.

If you are currently running IE7 or IE8 on Windows XP SP2 (XPSP2) and you are thinking of upgrading to XPSP3, read on.

Internet Explorer 7 Users

If you are currently running IE7 on XPSP2, Windows Update will offer you XPSP3 as a high priority update. If you choose to install XPSP3, Internet Explorer 7 will remain on your system after the install is complete. Your preferences will be retained. However, you will no longer be able to uninstall IE7. If you go to Control Panel->Add/Remove Programs, the Remove option will be grayed out.

This behavior is by design and here is why. When we install IE7 on Windows XP SP2, we backup the existing IE6 files in an uninstall directory. Those IE6 files are the ones that shipped on XPSP2 plus all the security updates you’ve installed while using IE6. Windows XP SP3 contains a newer version of the Internet Explorer 6 files. If you have XPSP3 on your system and uninstall IE7, your system would revert to the backed up (older) version of the IE6 files rather than the newer XPSP3 version. You would end up in a mixed file state in Windows where most files would be the upgraded XPSP3, except for the IE6 files restored when uninstalling IE7. This state is not supported and is very bug prone. To ensure a reliable user experience, we prevent this broken state by disabling the ability to uninstall Internet Explorer 7.

This is just some basic information for those who upgrade to SP3.

Comments welcome.

Blog entry is here.

[tags]windows, microsoft, sp3, ie7, xp, downgrade, [/tags]