How To Fix It: Windows Update 643 bug

Windows 10 is an ever-improving operating system platform that regularly releases updates to improve the overall experience. It introduces various features to make the platform easier to use, as well as security features to protect the system from malicious attacks.

However, you often encounter errors that prevent you from downloading and installing updates. One such error is Windows Update error code 643, a common error that occurs mainly because of a corrupted .NET structure. However, you may also see the error due to software conflicts.

It is always recommended to update your Windows 10 operating system regularly to ensure that your computer runs smoothly and flawlessly. However, some users have reported that an update error code 643 occurred while installing Windows Update. Specifically, you may receive a Windows Update error code 0x643 or 0x80070643 when trying to install an update for .NET Framework. This error code is usually caused by a corruption in the installation of the .NET Framework or an inconsistent state of the MSI database.

This update error code prevents you from updating Windows Update and may eventually make it unusable. The error message may also appear in the following format:

Error found: Windows Update code 643 encountered an unknown error.

Some users have reported on forums that they received error code 643 when trying to install Windows updates. Error code 643 is an update error, more common in Windows 7, 8, and 8.1. The error blocks Windows updates. Here are some solutions that can fix error code 643.

What is the cause of Windows Update error code 643?

What is the cause of Windows Update error code 643?

The appearance of error code 643 is due to the fact that the update, for one reason or another, can not be installed on the system. Usually, such causes are:

Third-party antivirus program interference: an error code may appear because a third-party antivirus program on your system is interfering with the update process. In this case, you need to temporarily disable the antivirus software and then run its update.

The .NET Framework is corrupted: The main cause of the error seems to be corruption during the installation of the .NET Framework. In this case, you need to uninstall the various versions of the .NET Framework using a utility, and then reinstall it.

There are many things you can do to get rid of this error. As mentioned, there are many causes for the error, and the solutions also vary depending on the specific scenario. In any case, you can try the solutions mentioned below. We hope that one or the other solution will work for you, depending on the cause of your problem.

The solution to Windows Update error code 643

The solution to Windows Update error code 643

Disable your security solution

First of all, you need to temporarily disable your third-party antivirus program. The fact is that third-party security tools often conflict with Windows Update, which can lead to the pesky Windows Update 643 error code. If that solves your problem, you should contact your vendor or switch to a different antivirus product.

Scan your computer for malware

Unfortunately, Windows Update is a very desirable target for attackers.
Therefore, Windows Update error 643 in Win 7 may be a sign that your computer is infected with malware.
Therefore, you should scan your system as soon as possible as it might be compromised.

If you have a reliable third-party antivirus installed on your computer, it is best to let it do its job without further delay.

If you think that Microsoft products are unbeatable in terms of protection against malware, you should check them with Windows Defender :

Run > type “Defender” in the search box > Windows Defender > Scan.

And to make sure that no hostile software is hiding in the background, you should use a powerful anti-malware tool.

Network Troubleshooting

If the Windows Update 643 error keeps occurring, you may be experiencing network problems.

Here’s how you can fix them:

  1. Open the Start menu -> Control Panel -> Network and Internet.
  2. Go to the Network and Sharing Center -> select “Fix Network Problem”.
  3. You are now in the Network Troubleshooting Guide -> Use its functions to repair your network
Update your network card driver

If the previous method was unsuccessful, the driver for your network adapter may be out of date, which means you need to find and install the latest version immediately.

The Windows Device Manager can do this automatically:

  1. Open the Start menu > right-click on “Computer”.
  2. Select “Manage” from the list of available options > The “Computer Management” screen will open.
  3. Go to Device Manager -> Find your network adapter and right-click on it > Update its driver software.

Unfortunately, the Device Manager may not update your driver. Bad things can happen.
But don’t worry: You can either do the trick yourself by finding the version you need online or use a third-party tool to speed up this tedious process – in fact, a third-party tool will solve all your driving problems with one click.

Use Microsoft’s “Fix It” tool.

If you’ve made it this far, it’s time to ask for help from good old Microsoft support. Go to Microsoft’s official website and download the Microsoft Fix It wizard. Follow the wizard’s instructions to fix the Windows Update 643 error.

Uninstall Microsoft .Net Framework 4 client profile.

And here’s another supposedly effective fix: your Microsoft.Net Framework 4 client profile may be corrupted, which means you’ll have to uninstall it. Here’s how to do it in Windows 7 :

  1. Start Menu > Control Panel > Programs > Programs and Features.
  2. Find Microsoft.Net Framework 4 client profile > Uninstall it
  3. Restart your computer > Try to update your system with Windows Update.
Reset Windows Update components

This method requires the use of the extended order prompt. To open it, proceed as follows:

  1. Press the Windows logo key + R to open the “Run” window > Type “cmd” (without the quotes) > Enter.
  2. Find “cmd” and right-click on it > Select Run as administrator

Now you should enter the following commands (be sure to press the Enter key after each command) :

network shutdown bits
net stop wuauserv
net-stop application
cd /d %windir%system32
regsvr32.exe atl.dll
regsvr32.exe urlmon.dll
regsvr32.exe mshtml.dll
regsvr32.exe shdocvw.dll
regsvr32.exe browseui.dll
regsvr32.exe jscript.dll
regsvr32.exe vbscript.dll
regsvr32.exe scrun.dll
regsvr32.exe msxml.dll
regsvr32.exe msxml3.dll
regsvr32.exe msxml6.dll
regsvr32.exe actxprxy.dll
regsvr32.exe softpub.dll
regsvr32.exe wintrust.dll
regsvr32.exe dssenh.dll
regsvr32.exe rsaenh.dll
regsvr32.exe gpkcsp.dll
regsvr32.exe sccbase.dll
regsvr32.exe slbcsp.dll
regsvr32.exe cryptdlg.dll
regsvr32.exe oleaut32.dll
regsvr32.exe ole32.dll
regsvr32.exe shell32.dll
regsvr32.exe initpki.dll
regsvr32.exe wuapi.dll
regsvr32.exe wuaueng.dll
regsvr32.exe wuaueng1.dll
regsvr32.exe wucltui.dll
regsvr32.exe wups.dll
regsvr32.exe wups2.dll
regsvr32.exe wuweb.dll
regsvr32.exe qmgr.dll
regsvr32.exe qmgrprxy.dll
regsvr32.exe wucltux.dll
regsvr32.exe muweb.dll
regsvr32.exe wuwebv.dll
winsock grid reset
winhttp proxy net reset
network start bits
network start wuauserv
PVC clean startup applications
startup cryptogram

After getting the green indicator to continue, close the order prompt. Go to the Microsoft support website and download the latest version of the Windows Update Agent. Install it on your computer. Then reboot your computer. Now visit your Windows Update Center – it should work now.

Fixing the system registry

All in vain? In this case, you should consider changing your registry: it may be corrupted.
Keep in mind that modifying the system registry is an extremely risky procedure – even a small error can lead to a good malfunction or even cause Windows 7 to fail. We, like most people, believe that such a result is absolutely undesirable. That’s why we recommend using a special tool to safely and effectively restore your Windows registry. For example, a third-party program will do it for free.

Setting the system to a previous state

To do this, you need to use the System Restore: When this feature is enabled, you can reset the operating system to an earlier date and undo the last changes made to the system. Just follow the instructions below to use System Restore on Windows 7:

  1. Open the Start menu > Go to the search box > Enter System Restore.
  2. Go to System Restore > Select the Restore system files and settings option > Click Next to continue.
  3. Select the last restore point where your operating system did not have the Windows 643 update error > Confirm

Frequently Asked Questions

  1. Run the Windows Update diagnostic.
  2. Run the SFC scan.
  3. Remove the software distribution folder.
  4. Disable updates for other Microsoft products.
  5. Remove problematic updates.
  6. Manually download and install Windows updates.

  1. Use System File Checker and DISM.
  2. Run the Microsoft Windows Update online diagnostic tool.
  3. Disable antivirus or firewall.
  4. Disable proxy or VPN.
  5. Reset the Windows Update folders.
  6. Reset Windows Update components.

  1. Open the settings.
  2. Click Update and Security.
  3. Click Troubleshooting.
  4. Under Start and Run, select Update Windows.
  5. Click Run Troubleshooter. Source: Windows Central.
  6. Click the "Close" button.

  • Run the Windows Update troubleshooter.
  • Restart the services related to Windows Update.
  • Run the System File Checker (SFC).
  • Run the DISM command.
  • Temporarily disable your antivirus program.
  • Restore Windows 10 from a backup.