# Solved: .NET Installation Repair



## Flamefury (Aug 29, 2008)

I'm running Windows 7 64-bit with Service Pack 1.

For a select few applications (e.g., Microsoft Web Platform Installer, SQL Server Express 2008 R2), the application will stop working. First event log error: 
.NET Runtime version 2.0.50727.5444 - Fatal Execution Engine Error (6868EA52) (80131506)

Which is soon followed by: 
Faulting application name: WebPlatformInstaller.exe, version: 7.1.1070.1, time stamp: 0x4d96afbe
Faulting module name: mscorwks.dll, version: 2.0.50727.5444, time stamp: 0x4d4f1425
Exception code: 0xc0000005
Fault offset: 0x000ca0c5
Faulting process id: 0x%9
Faulting application start time: 0x%10
Faulting application path: %11
Faulting module path: %12
Report Id: %13

In the SQL Server Express 2008 R2 case, the second error is: 
Faulting application name: caspol.exe, version: 2.0.50727.5420, time stamp: 0x4ca2b913
Faulting module name: mscorwks.dll, version: 2.0.50727.5446, time stamp: 0x4d8cdc73
Exception code: 0xc0000005
Fault offset: 0x000ca0c5
Faulting process id: 0x%9
Faulting application start time: 0x%10
Faulting application path: %11
Faulting module path: %12
Report Id: %13

So the error should be in mscorwks.dll.

Since this looks to be something wrong with .NET, I tried looking into what I could do to fix it without having to reformat. This link: 
http://support.microsoft.com/kb/306160

Proved useless, since the installation package detects that .NET 2.0, 3.0 and 3.5 are part of the OS and therefore no modifications can come from the installer pack.

I took a look at this post, which is applicable to Windows 7 as well:
http://blogs.msdn.com/b/astebner/ar...t-framework-2-0-and-3-0-on-windows-vista.aspx

I did the sfc /scannow at administrator level and found several corruptions. I had to grab my Win7 installation DVD, mount the install.wim file on it and then copy the corrupted files from the DVD to the computer. Nearly all of them were fixed, but two errors persist (quite possibly because they were updated in SP1, which my DVD doesn't include). The attached log will hopefully shed some light.

I don't really know where to go from here. Any help you can provide would be greatly appreciated.


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## Samsung (Nov 14, 2002)

First try uninstalling .Net all versions and letting Win Update reinstall.
If that don't help I have used this once on a client PC
.NET Framework Cleanup Tool
http://blogs.msdn.com/b/astebner/archive/2008/08/28/8904493.aspx


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## Flamefury (Aug 29, 2008)

It's impossible (if not, highly recommended against) to uninstall .NET framework 3.5.1 (and by extension, 2.0 and 3.0) from a Windows 7 OS as many parts of the system rely heavily on it. The only one I can do that with is 4.0, but that hasn't helped.


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## Samsung (Nov 14, 2002)

Since your dvd was not SP1 that may be problem, also there have been several security updates to several versions. .Net is a mess we won't see an end to anywhere in the near future.
When all else fails I used that tool. *This tool is designed as a last resort*

EDIT: By all means backup everything or create system images before resorting to extreme measure


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## Flamefury (Aug 29, 2008)

Quoted from Aaron Stebner, who made the tool, on that very page you linked:


> The cleanup tool will run correctly on Windows 7. However, it will not allow you to remove the .NET Framework 3.5 on Windows 7 because that version of the .NET Framework is an OS component, and the cleanup tool does not allow you to remove versions of the .NET Framework that are installed as OS components.


In other words, impossible. The most I can do is hide .NET Framework 3.5 and 3.0, but 2.0 (the problematic one) must always be on and needs to be active to use any of the installers I'm trying anyway.


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## Flamefury (Aug 29, 2008)

Figured it out.

On a wild guess, I assumed my Service Pack 1 installation was corrupt so I uninstalled it from my machine. SP1 was the only thing in recent memory that updated the .NET packages to significant extents. The installer packages that crashed are now able to run without any problems and there are no more "Fatal Execution Engine Error"s in my event log.

The autochk.exe corruption as seen in my SFC scan log is still unresolved, but this appears to be an issue with Windows 7 and the hibernate function. Nothing to do with .NET, so I'll just mark this solved.

Thanks for trying to help, Samsung. Sorry if I sounded snappy.


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## bjbakker (Jul 23, 2011)

I also have this problem, only seems to be there when using an Win7 SP1 DVD to install windows. 
With just updating Windows 7 with SP1 I haven't had the problem just yet. But it is such a long time to do this, MS just really needs to address this problem! 

problem error: .NET Runtime version 2.0.50727.5446 - Fatal Execution Engine Error (000007FEF7F840D2) (80131506) 

when: opening Outlook 2010
(in previous install: opening Remote Desktop manager, running windows update, running Windows installer, etc etc) 

updates: all 

formats: 4 

time spend: toooo much!


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## Flamefury (Aug 29, 2008)

I've realized it's become a game of figuring out what version is crashing, which update it corresponds to, then uninstalling that update and seeing if the error persists.

Since your version is crashing on v2.0.50727.5446, it corresponds to this update:
http://support.microsoft.com/kb/2518869

From Control Panel, go to Uninstall Programs and then View Updates on the side bar. Uninstall the update that corresponds to KB2518869 (will be denoted at the side of each update), reset your system and try running the program once more.

This is not a good solution, by any means, but it's the only one fix I've been able to find that solves these kinds of problems.

(Just so you know, I suffered the exact same error you did, down to the version number, when I installed this particular update.)


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## bjbakker (Jul 23, 2011)

hi, removing the update 2518869 seems to have solved the Outlook startup problem. so now i still have some other errors, but at least i can e-mail again. 

tnx!! 

NB. didn't notice that update, because it was installed a lot earlier then when outlook stopped working. but at least (uninstalling and disabling) it solved the problem.


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