Updated versions of .NET Framework cleanup and verification tools that work with the .NET Framework 4

Over the past week or so, I finally found some time to update the .NET Framework cleanup and verification tools to support the recently released .NET Framework 4 product family.  I have uploaded new versions of both tools, and you can find more information about the tools and download links in their users guides.  Here are links for the users guides for each of these tools:

As always, please let me know if you run into any bugs, questions or feature suggestions while using either of these tools.  I would prefer that you post a comment on the user’s guide blog posts so the comments will be visible to other users as well, but you can also send me an email.

Comments (18)

  1. K8e M says:

    I just can't thank you enough for these tools, so I won't even try.  Suffice it to say, you have my undying gratitude.

  2. june says:


    I cant fully uninstall my .net framework 4.0 with both software above. I just want to install .net framework 3.0 but it says "newer version installed". I would appreciate it if you could help.

  3. Hi June – If you're getting a "newer version installed" when trying to install the .NET Framework 3.0, then that means you already have the .NET Framework 3.0 SP1 or 3.0 SP2 installed and you don't need to install the older version of the .NET Framework 3.0.

  4. Ivan says:

    Is is compatible with x64 .net frameworks? If so, how is it supposed to clean up dlls from %windir%system32 while being a 32-bit application?

  5. Hi Ivan – Yes, these tools are compatible with the x86, x64 and ia64 versions of the .NET Framework.  There is logic within the tools to load from the 64-bit file system and registry if they detect that they are running on a 64-bit version of Windows.

  6. Pam says:

    I THINK I need to use this clean up tool – I just upgraded to Win 7 ultimate and Expression web 2 won't install – should I uninstall net framework 4 and then try to install EW2?

  7. Hi Pam – I'm not sure if this Expression setup error would be caused by the .NET Framework 4 or not.  It is definitely worth a try to repair/re-install the .NET Framework 4 and see if that helps.  If not, you'll probably need to look at the Expression setup logs to see if there is more information there about the root cause of the install failure.

  8. Evan says:


    Thanks for your work developing this tool.  

    Is it supposed to clear out C:WindowsMicrosoft.NETFramework and Framework64  (win7 64)?   I still have a full complement of 2.0, 3.0, and 3.5 directories underneath.



  9. bill says:

    Windows Vista Update April 11, 2011 failed installation of "Security Update for Microsoft .NET Framework for Windows XP, Server 2008, Windows Vista, Windows 7, Windows Server 2008 86x"  This mentions KB2526954.

    I went to Programs & Features and tried to Install/Uninstall/Change Microsoft Framework 4 Client Profile.  When I clicked on it, I got the Uninstall/Change prompt. With the next click, the operation failed with Error Code 66A.  Attempted installation of the Update fails in the same manner.

    What to do?

  10. Hi Bill – I'd suggest using the cleanup tool and the steps listed at blogs.msdn.com/…/8108332.aspx to fully remove the .NET Framework 4 from your computer, then re-install it and try again to install that security update.

  11. Bill says:

    I decided to take the download for IE-9 along with another new copy of the .NET Framework Update.  With IE-9 installed, the update of the Framework patch went without a glitch.  Very good news, even as I don't use IE.  (Thank you for responding!)

  12. Bill says:

    So I got brave and removed .NET Framework 3.5 SP1 and .NET Framework 1.1.  I then installed .NET Framework 4.  A look at my installed programs confirmed.  However, on going to Window Update, they wanted to download .NET Framework 3.5 SP1.  I complied.  It seems that Windows Update thinks I am up to date now.  I now have showing in Installed Programs, .NET 3.5 SP1, .NET Framework 4 Client Profile and .NET Framework 4 Extended. And it seems all is well.


  13. JOHN20 says:

    Hi Aaron

    Vista Home OS

    I have been having problems with my computer since my update of .net Framework 4. I get the 643 error when trying to update further Framework updates recently and have tried repairing and removed the only .net frameworks that show up in Add Remove 3.5/4 and reinstalled them with no difference. I have removed .Net framework 4 and stopped all auto updates and my computer works better without it. I especially had problems with IE7 after the framework 4 update in June I tried IE8 before and after the 4 update and it slowed down my IE/comp badly. I installed IE 9 after the framework 4 update and it did not do anything to help.

    I ran the sfc /scannow with nothing showing up wrong.

    I have files posted here. I hope this is posted correctly. Any help would be appreciated.


  14. Hi John20 – I didn't see any errors in the log files that you uploaded.  What I'd suggest doing is using the cleanup tools and the steps listed at blogs.msdn.com/…/8108332.aspx to fully remove the versions of the .NET Framework that are installed on your computer, then try to re-install the .NET Framework 3.5 SP1 and the .NET Framework 4.  Afterwards, please try to visit Windows Update again and see if you are able to successfully install .NET Framework updates from there.

  15. Rob says:

    First of all, thank you for making these tools.

    Just a couple of questions.

    Will the Client Profile v3.5 be supported? Right now, both tools seem to ignore its installation completely. Although the cleanup tool still seem to be able to remove it, but the entry in "Add/remove programs" remain.

    The second is more an observation. Despite not being "officially" supported, language packs are still uninstalled by the cleanup tool. Somewhat. After performing an "all uninstall" on v3.5 SP1 + language packs, the one for v3.5 seems to uninstall completely, the one for v3.0 still keep its entry in "Add/remove programs", although its directories under "Microsoft.NET" and "Reference Assemblies" folder are deleted, and the v2.0 language files and uninstall entry are intact. But may be this is just an artifact how the Windows Installer work? And both v3.0 and v2.0 language packs can be removed correctly afterwards by running their respective uninstallers, so it is not really an issue, more a behavior oddity.

    The only files left behind are ngen_service.log and ngen.log  in Microsoft.NETFrameworkv2.0.50727 directory, but this is probably by design.

  16. Hi Rob – I didn't have any plans to support the .NET Framework 3.5 client profile.  That profile has limited usage, and computers that have that profile installed and then connect to Windows Update get upgraded to the full version of the .NET Framework 3.5.  If you run into specific issues with the .NET Framework 3.5 client profile that the current cleanup tool does not allow you to recover from, please let me know and I can evaluate what it would take to make the tool support that profile in the future.

    The cleanup tool does not remove any of the language pack information from the computer.  I'm not sure how to explain the behavior that you're seeing in that scenario.

    Please keep in mind that the cleanup tool is not designed as a full replacement for the normal product uninstall process.  It is only designed to remove enough of the product to allow a future install to succeed.  That means that things like Add/Remove Programs entries, log files, etc might be left behind after running the cleanup tool because those items don't prevent future installs of the product.

  17. jorge teran says:

    Every time that I turn off  my computer is updating Net Framework 4 and hold me for almost 10 minutes, why doesnt it update at once???? Help!

  18. Hi Jorge Teran – I'd suggest trying to use the tools and steps listed at blogs.msdn.com/…/8108332.aspx to repair/re-install the .NET Framework 4, and hopefully that will clear up this repair that you see after each reboot.