Vista - IE8 now requires "run as administrator" after SP2

I installed Vista SP2 (via Windows update) on two separate computers. With both, after accessing IE8 once (without a problem), I was unable to access it again until I right-clicked and ran as administrator. (Very annoying.) I can turn off UAC, but is there some way of undoing this without turning off UAC completely? (It shows I have full permissions under "properties" - "security."

Try uninstalling IE8 and reinstall it and see. You can uninstall it in "Installed Updates".

It isn't listed in "programs and features," and it wasn't installed originally by Windows update (I just checked the list of things that were installed). When I try to download IE8 from the Microsoft site, it tells me that the current version is more recent than the one I'm downloading. I do have an option (right-clicking on the IE8 icon) to "Restore Previous Versions," but I'll wait to do that. Since this happened on two separate machines having little in common, except Vista (and SP2) (one a desktop, the other a laptop), it's hard to believe this has only happened to me. (It happened, by the way, on my Windows 7 (build 7127) system last night, too.)

You can find it in
Control Panel-> Programs & Features->Installed Updates

It is shown as an update and you can right click to uninstall.

Or use MS FIXIT to remove IE8.

Thanks for the suggestions. I uninstalled, and then reinstalled, IE 8 on one of my computers. Strangely, for the first 3 or 4 times "opening" IE 8, it was fine, and then it went back to requiring me to "run as administrator" in order to open. (Nothing on the computer changed between those times, including no IE 8 updates or anything like that.) I'd think "virus," except it has happened on three different machines (two running Vista, one running Windows 7 RC), virtually simultaneously. I disabled "active" scanning on Sophos--the anti-virus software running on all three machines--on the one I just reinstalled IE 8, but it made no difference.

I am experiencing exactly the same thing on Vista Business 64-bit, after installing SP2 for Vista. I also have Sophos for antivirus/antispam. Plus, when clicking on hyperlinks, IE8 does not open.

There was a Compatibility Update that showed up right after SP2 for IE8 for me try.

I haven't seen a post-SP2 IE 8 "compatability" update yet, but I'll continue to check.

It turns out several people have had this problem, both in Vista and in Windows 7. The common feature seems to be using Sophos as the anti-virus program (although I have four machines, all running Sophos, and three of them have the problem; one doesn't). It all started with loading SP2 yesterday morning--and in the case of Windows 7, also yesterday morning, which suggests Microsoft (or maybe Sophos) pushed out a "change" that has caused this problem with IE8 and Sophos.

Until it is actually addressed (by Microsoft or Sophos), perhaps the best temporary "fix" is to go into "Manage Add-Ons" in IE8 and disable "Sophos Web Content Scanner." That fixed it for me, and some others--at least, if you are running Sophos.

I had exactly the same senario, all worked fine until automatic update yesterday and then IE would only 'run as aministrator'. Again the common theme would seem to be that I am using Sophos. Disabling Sophos web scanner cured the problem