Running .MSU File to Install Windows Update Manually

Windows normally downloads and installs updates automatically through Windows Update. However, there are situations where you may need to install an update manually. For example, Windows Update might fail repeatedly, an update may not appear on your computer yet, or you may need to install a specific update package.

Microsoft commonly distributes certain Windows update packages as .msu files. An MSU file is a Microsoft Update Standalone Package that contains the files and instructions Windows needs to install a particular update.

If you already have the correct .msu file, you can usually install it simply by opening the file. Windows uses the Windows Update Standalone Installer, also known as WUSA, to process the package.

For very new users, the important thing to remember is that you should install an MSU package that matches your Windows version, system architecture, and update requirements. Installing an unrelated package can result in an error or an unsuccessful installation.

Install Windows Update Manually from an .MSU File

To install a Windows update manually from an .MSU file, first download the correct update package for your version of Windows. Locate the downloaded .msu file in File Explorer, double-click it, and allow the Windows Update Standalone Installer to check the package. Follow the on-screen instructions and restart the computer if Windows asks you to do so. 

If double-clicking the file does not work, you can install the package through Command Prompt by using the WUSA command.

Step 1: Check Your Windows Version

Before running an MSU file, first check which version of Windows you are using. This is important because Windows updates are normally designed for specific Windows releases.

Press Windows + R on your keyboard to open the Run dialog box. Type winver and press Enter.

A window will appear showing your Windows version and OS build information. Make a note of the version displayed there.

You can also open Settings, select System, and then select About. Look for information such as Windows edition, Version, and System type.

Knowing this information helps you choose the correct update package.

Step 2: Check Whether Your PC Uses 64-bit or ARM64 Windows

The next thing you should check is your computer’s system architecture.

Open Settings and go to System > About. Look for System type under the device specifications.

Most modern Windows computers use 64-bit x64-based processors, but some devices use ARM64. The update package must match your system architecture when Microsoft provides separate packages.

For example, an update package intended for an ARM64 device should not be installed on a standard x64 Windows computer.

If you download an incompatible MSU package, Windows may reject it rather than installing it.

Step 3: Download the Correct .MSU File

Once you know your Windows version and system architecture, obtain the appropriate .msu update package.

Microsoft provides updates through its official update channels, including the Microsoft Update Catalog for many standalone update packages.

When searching for an update, carefully compare the KB number, Windows version, architecture, and other requirements shown for the package.

A KB number identifies a particular Microsoft knowledge base update. For example, an update may be identified by a number such as KB50xxxxx.

Do not simply download the newest-looking MSU file. Make sure it is intended for your particular version of Windows.

Step 4: Locate the Downloaded MSU File

After downloading the update, open File Explorer.

Go to your Downloads folder unless you selected another location when saving the file.

Look for a file ending in .msu. You may see a filename containing the KB number and other information about the update.

For example, the filename could contain details indicating the Windows version, architecture, and update number.

If you cannot find the file, use the search box in File Explorer and search for .msu.

Once you find the file, do not extract it simply because it looks like an archive. An MSU package is designed to be processed by Windows’ update installer.

Step 5: Double-Click the .MSU File

The easiest way to install an MSU package is to double-click the file.

Windows should open the Windows Update Standalone Installer.

The installer may first display a message such as Windows Update Standalone Installer and then check the update package.

Depending on the update, Windows may take some time to determine whether the package can be installed on your computer.

If Windows asks for permission through User Account Control, select Yes if you intentionally downloaded the correct update.

Step 6: Follow the Windows Update Standalone Installer

After Windows checks the package, you may see an installation prompt.

Read the message carefully. If Windows confirms that you want to install the update, select Yes or the appropriate confirmation option.

The installer will begin processing the MSU package.

Do not close the installer while the update is being installed. You may see a progress window, and the installation can take several minutes depending on the update.

It is normal for Windows to take some time during certain update operations.

Step 7: Restart Your Computer

After installation finishes, Windows may ask you to restart your computer.

Save any open documents and close your applications before restarting.

If Windows provides a Restart now option, you can select it. You can also restart later if the installer allows you to postpone the restart.

Some updates do not become fully active until Windows has restarted, so do not assume that the installation is complete simply because the installer has finished copying files.

After the computer starts again, Windows should complete any remaining update operations.

Step 8: Check Whether the Update Was Installed

After restarting Windows, you can verify whether the update was successfully installed.

Open Settings and go to Windows Update. Depending on your version of Windows, open the Update history section.

Look through the list of installed updates and find the KB number associated with the MSU package you installed.

You can also search for the KB number in the installed update list.

If the update appears in the history, Windows has recorded the installation.

This is useful if you are manually installing an update to solve a particular problem because it confirms whether Windows accepted the package.

Install the MSU File Through Command Prompt

If double-clicking the MSU file does not work, you can use Command Prompt and the Windows Update Standalone Installer.

First, find the location of the MSU file. For example, it might be in your Downloads folder.

Press the Windows key, type Command Prompt, and select Run as administrator.

You can then use the WUSA command to install the package.

The basic command has this structure:

wusa “C:\Path\To\Update.msu”

Replace the example path with the actual location and filename of your MSU file.

For example, if the file is located in your Downloads folder, the command would use the path to that specific file.

The quotation marks are useful when the file path contains spaces.

Use the Quiet Installation Option When Needed

WUSA also provides options for controlling how the MSU package is installed.

For example, the following command starts an installation without displaying the normal standalone installer interface:

wusa “C:\Path\To\Update.msu” /quiet

You should be careful when using /quiet because it reduces the amount of information displayed while the installation is running.

If you want Windows to restart automatically when the update requires it, additional WUSA options are available. However, a beginner should normally avoid adding extra switches unless they understand what each option does.

For a first manual installation, simply running the MSU package normally is usually easier because Windows can display messages when something goes wrong.

Check the Error if the MSU File Will Not Install

Sometimes Windows will refuse to install an MSU package.

One common reason is that the update does not apply to your particular version of Windows. Another possibility is that the update is already installed, has been replaced by a newer update, or requires another update first.

You may also encounter an error if the MSU package is intended for a different system architecture.

Read the exact error message instead of repeatedly running the same file.

If Windows says that the update is not applicable to your computer, return to the update information and verify the Windows version, build, architecture, and prerequisites.

Make Sure the Update Is Not Already Installed

Before attempting the installation again, check whether Windows already has the update.

Open Settings, go to Windows Update, and open Update history.

Search for the relevant KB number.

If the KB number is already listed, you probably do not need to install the same package again.

This can also explain why WUSA reports that the update is already installed or not applicable.

Installing the same update repeatedly is generally unnecessary.

Run the MSU File Again After Resolving the Problem

If you discovered that the wrong file was downloaded, obtain the correct MSU package and try again.

If Windows required a previous update or restart, complete that requirement before running the package again.

It is also a good idea to keep the computer connected to a reliable power source during the installation, particularly when installing a large cumulative update.

Once the correct package has been installed and Windows has restarted, check Update history again to confirm the result.

FAQs

What is an .MSU file?

An .MSU file is a Microsoft Update Standalone Package. It is used to distribute certain Windows updates that can be installed manually through the Windows Update Standalone Installer, also known as WUSA.

Can I install an MSU file by double-clicking it?

Yes. In most cases, you can double-click the MSU file, and Windows will open the Windows Update Standalone Installer automatically.

Do I need Command Prompt to install an MSU file?

No. Command Prompt is not normally required. It is useful when the standard double-click method does not work or when you need more control over the installation process.

What does WUSA mean?

WUSA stands for Windows Update Standalone Installer. It is the Windows component used to install MSU update packages.

Why does Windows say the update is not applicable to my computer?

This can happen when the update does not match your Windows version, build, system architecture, edition, or prerequisites. It can also occur when the update has already been installed or replaced by another update.

Can I install an MSU file without an internet connection?

In many cases, yes. If you already have the complete and appropriate MSU package, the installation itself can generally be performed locally. However, some updates may have prerequisites or dependencies that need to be installed separately.

Where should I save the MSU file?

You can save the file anywhere you have access to, such as your Downloads folder or Desktop. The location does not normally matter as long as you can access the file.

Should I restart Windows after installing an MSU file?

If Windows requests a restart, you should restart the computer. Some updates cannot finish their installation until Windows restarts.

Can I delete the MSU file after installation?

If the update has installed successfully and you no longer need the package for another computer or future troubleshooting, you can generally delete the downloaded MSU file. Removing the downloaded package does not uninstall the update.

Summary

Installing a Windows update manually from an .MSU file is relatively straightforward. First, identify your Windows version and system architecture, then download the correct update package. Locate the MSU file in File Explorer and double-click it to launch Windows Update Standalone Installer.

Follow the installation instructions and restart the computer if Windows requests it. After restarting, open Windows Update history and verify that the relevant KB update appears.

If double-clicking the package does not work, you can use Command Prompt with the WUSA command to launch the installation manually. If Windows reports that the update is not applicable, check the update’s compatibility requirements rather than repeatedly trying the same file.

The most important part of manually installing an MSU package is choosing the correct update for your Windows version and system architecture.