Windows Update Failing in Vista or Windows 7

The Windows operating system gets updated frequently. Microsoft regularly releases updates for various versions of the Windows operating system to patch security holes, fix bugs, enhance existing functionality or add new functions.

By default, Windows update runs on a scheduled basis on Vista and Windows 7 and installs updates automatically. Although the user can change the Windows Update configuration to only check for updates or check and download, normally letting Windows install updates automatically is a good idea.

But like any software, the Windows Update service has a few dependencies on the end-user’s computer. In Vista and Windows 7, Windows Update depends on several services to run, as well as a number of file locations and registry configurations.

Installing updates means that compatibility issues with existing software or running programs need to be addressed, and of course, the installer service needs to work properly. Any issues with the Windows registry, or the C:\Windows\WinSxS\Manifests, or C:\Windows\Servicing\Packages locations can cause the Windows update service to fail.

Although there are different errors that can be reported when Windows Update fails to execute properly, the most common errors are:

As you can see part of the problem is that the error message are not always very helpful. In many cases, the update service simple reports the error message “Windows Update encountered an unknown error.”, which does not tell the user anything.

A possible screenshot of failed Windows Update may look like this:

Of course, it is possible that not all updates fail, but only a specific update.

How to solve Windows Update Problems in Vista and Windows 7

The solution to Windows Update errors depends on the error you are getting. But a few things are common and can be checked or corrected in all cases.

Please note that for most of these steps you will need to use a user account with administrative privileges.

The first thing to check is that you have a working Internet connection. If not, Windows update cannot connect to the Microsoft update websites. This includes problems caused by proxy servers, security software, and external firewalls. Microsoft recommends turning on the Windows firewall and disabling 3rd party firewalls and software accelerators in case of update problems.

Also, make sure that you add the Windows update-related websites to the Trusted sites on your computer. That will prevent any network traffic from these sites to be blocked. You can use the Internet Explorer to add trusted sites. Select the Tools menu -> Internet Options -> Security tab -> Trusted sites icon -> Sites button. Ad http://*update.microsoft.com, https://*update.microsoft.com, and http://download.windowsupdate.com as trusted sites.

Next, check the services that should be running. You can start the service manager by typing “services.msc” and pressing Enter at the Start menu. This will start the Microsoft Management Console.

In the services list, make sure that the Windows Update service, the Windows Modules Installer, and the Background Intelligent Transfer service are started.

Open the command prompt window as an administrator (type “cmd” in the Start menu, right-click the “cmd.exe” that shows in the list, and in the popup menu select Run as administrator), and then type SFC /SCANNOW at the command prompt, followed by Enter. This will check the Windows system files on the computer.

Apart from that, there are specific solutions to specific problems.

Error code 0x80070424 for example means a problem with the Windows update service DLL. Reregistering the DLL generally fixes the issue. So, start a command prompt again, and then type:

%SYSTEMROOT%\SYSTEM32\REGSVR32.EXE %SYSTEMROOT%\SYSTEM32\WUAUENG.DLL /S

Press Enter and wait for the DLL registration to complete. Then try Windows Update again.

A number of Windows Update problems can also be fixed by using the Windows Update Readiness Tool. This Microsoft application can be downloaded and installed on your computer, after which it will check your computer for any known problems that can cause Windows Update to fail on Vista or Windows 7. The tool will not find and fix all causes though.