# Solved: .NET Framework Update and Install Fails



## BML (Nov 25, 2001)

My windows 7 system had .Net Framework v. 4.5.1 installed and windows update notified me of a security update. Every time I try to install it, it fails with an error code 643. I did some googling and found a couple of things, including a Microsoft Fix-It (that didn't work) and a .NET Repair tool (that didn't work). So I went and uninstalled it completely. Then windows update shows an update available of course, the .NET 4.5.1 so I re-installed and it failed the install. When I re-boot I get an error saying I need to install .NET 4.0.30319.

what's going on? Why does it keep failing the install?


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## flavallee (May 12, 2002)

*Microsoft .NET Framework 4.5.2* is the most current version for Windows 7.

Download and save the full 66.8 MB file, then close all open windows first, then install it.

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## BML (Nov 25, 2001)

I just tried it. It failed just like the others did. I zipped and attached the error log.


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## BML (Nov 25, 2001)

Any ideas? Anybody? Could it possibly be because I do not have .Net 3 or .Net 2 installed? According to my program list I only have .Net 1.1. I tried to install both 4.0 and 4.5.2 and they fail with a fatal error. I'm wondering if they require the previous version.


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## flavallee (May 12, 2002)

*Microsoft .NET Framework 3.5 SP1* comes as part of Windows 7.

3.5 SP1 also contains versions 2.0 SP2 and 3.0 SP2.

None of those 3 versions will appear in the "Programs And Features" list.

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## plodr (Jun 27, 2014)

Go here and download and install the .NET verifier tool
http://blogs.msdn.com/b/astebner/archive/2008/10/13/8999004.aspx

You should have .NET 3.5 because it is part of Windows 7.

.NET 4 and 4.5 can't co-exist. (Another ridiculous MS maneuver).
So let's first see what Aaron Stebner's tool says is installed on your computer.

You can also look in HKLM\Software\Microsoft\NetFramework
there should be folders for v1.0, 2.0.50727, 3.0 and perhaps 4.0 or 4.1

4.5 is hiding in HKLM\Software\NetFramework\v4\SKUs


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## BML (Nov 25, 2001)

That tool verified that versions 1.1SP1, 2.0SP2, 3.0SP2, and 3.5SP1 are installed.

It says 4.0 Client, 4.0 Full, 4.5, 4.5.1, and 4.5.2 are not installed.

So, if 4 can't coexist with 4.5 then I should be only having to install 4.5.2 but I can't.


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## flavallee (May 12, 2002)

When I had version 4.0, the install of 4.5.2 overwrote and replaced it.

4.0 and 4.5.2 won't both remain.

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## BML (Nov 25, 2001)

Ok, now we just have to figure out why none of the "4" versions will install and come back with fatal error or error code 643. I've done it both thru windows update and from downloading the full file from MS.


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## BML (Nov 25, 2001)

Got it!!!! After doing some googling I found this from someone else: In C:\Windows\Microsoft.NET" there is a directory called "Assembly". It has some version 4 files in it. So I renamed the directory "Assembly2" and then tried the install - and it worked with no errors!

I went to Microsoft Update to make sure i had all the applicable security updates. It appears to be all good now!

Hopefully this can help anyone else with the problem, there were quite a number of people in various forums reporting similar issues.


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## flavallee (May 12, 2002)

> Got it!!!! After doing some googling I found this from someone else: In C:\Windows\Microsoft.NET" there is a directory called "Assembly". It has some version 4 files in it. So I renamed the directory "Assembly2" and then tried the install - and it worked with no errors!
> 
> I went to Microsoft Update to make sure i had all the applicable security updates. It appears to be all good now!
> 
> Hopefully this can help anyone else with the problem, there were quite a number of people in various forums reporting similar issues.


 :up:

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