Windows 7: Problem with .NET, BadImageFormatException + iertutil.dll

Hi,

A few days ago Windows installed a bunch of updates that caused inability to run a couple of programs. It looks like all of them use .Net. The problems are:
1) One program can't start popping up error window with message "An error occurred: System.BadImageFormatException. HRESULT=0x800700B6"
2) A bunch of other programs (like Adobe Acrobat Reader installation or some native Windows tools) fails with error about missing entry 379 in library iertutil.dll.



I did "sfc /scannow" which didn't find any problems. I tried to uninstall updates that were installed on the unlucky day but the problem is still on.
As I know .NET 3.5 is an integral part of Win 7 and can't be reinstalled. I have also googled that iertutil.dll is a part of internet explorer which points to another problem: Windows Update has not been able to install IE9 for a couple of months (error code 9C48). I was disregarding this because I use different browser and no other problems I noticed. But maybe now it's a problem due to iertutil.dll.
I downloaded Windows6.1-KB947821-v20-x64 tool that is recommended to run when there are some problems with windows update but it didn't help.

Thanks in advance for any suggestions what shall I do next.

Welcome to the forum
Begin to sort the IE9 problem by seeing this solution:

windows internet explorer 9 for windows 7 x64-based systems FAILS?

Please Report back

Hi,

I have tried the procedure you pointed and it failed. I mean the command line script "FORFILES..." can't find anything matching given pattern. I took a look at %WINDIR%\servicing\Packages dir and didn't see IE-9. There are some Microsoft Internet Explorer files but they don't have "9" in the name.
I have also downloaded IE9 installation file manually from Microsoft download page and when I tried to install it manually it failed with message that newer version is installed on the computer...
The existing version on the computer seems to be broken as I can't start it. Nothing happens - no error window and stuff like that.

Update:
In the "turn on/off windows features" window I see Internet Explorer 8 but I can't stop it - it just displayed error windos with message that error happened. No error code, no further hints.

Update1:
Is there anything like Windows log file ? I looking for the reason why I can't turn off Internet Explorer 8 in "Windows features".
For me it looks like I had IE8 and IE9 installation some time ago failed leaving some inconsistent state in a sense that IE9 is not in fact installed although the information that IE9 is installed is stored somewhere ( registry ?).
When I try to uninstall manually (pkgmgr) IE8 packages I get failure 0x8007005. I suppose it might be because the IE8 is still turned on ("Turn on/off windows features window").
Does anyone know what does it really mean ? I don't see any IE processes running. Maybe I should try to remove something manually. I have backed up all of my data so I am open even for some risky suggestions.

wkkw
Maybe the IE9 wasn't completely installed and that's why there is a remnant files left.
IE8 came preinstalled with Windows 7 OS and IE9 is an upgrad version when downloaded it replaces the 8, but you can uninstall the 9 by opening control panel then programs and futures and in the left pane select view installed updates then in the section microsoft window search for windows internet explorer 9 then right click and delete now the 8 will be back. Download and install the 9 with WU and make a search for updates.
Good luck