Only one instance of wusa.exe is allowed to run

This type of Windows update error is mainly associated with older versions of Windows operating system and is the most common in Windows operating system 7. Upgrading from older versions of Windows OS was definitely more difficult than it is. now and always there was a risk of receiving random error codes.

The error “Only one instance of wusa.exe is allowed to run” can be corrected in several ways and occurs in several different scenarios, like internet explorer update, manually installing a standalone update, etc. This is why it is important to keep track of all methods and try them as soon as possible..

Solution 1: disable your third-party antivirus

Third-party security tools can spoil the fun and cause all kinds of errors on users' computers.. These mistakes are not that common, but when they appear, the true cause is very difficult to locate and easy to resolve.

You will need to disable or uninstall third-party antivirus tools before starting the process that throws the error. The error mainly occurs with McAfee users, the instructions are for them. The steps are quite similar from one antivirus to another.

1. Open the user interface of your McAfee antivirus by double-clicking its icon on the desktop or by double-clicking its icon at the bottom right of the taskbar.

2. From your home page, click on Real-time scan under Virus and spyware protection which will open a new window.

1. Low real-time scanning: on the screen at the top of the window, click Shutdown and choose the amount of time you need the most before clicking Shutdown.

2. Check if the error still appears.

Solution 2: look in the task manager for another instance of “wusa.exe”

As the name of the error code is self explanatory, a possible solution would be to check for a second instance of wusa.exe running and preventing the desired update from continuing. This method is not always successful, but it is very easy to verify.

1. Use the Ctrl key combination + Shift + Esc to open Task Manager. You can also use the Ctrl key combination + Alt + Delete and select Task Manager from the menu. You can also search for it in the Start menu.

1. Click More Details to expand Task Manager and find the wusa.exe entry in the Processes tab of Task Manager. If you see multiple entries, right click on them and choose the End Task option from the context menu that appears.

2. Click Yes to display the message: “WARNING: Completing a process can cause unwanted results, including data loss and system instability …”

1. Restart your computer and see if you can continue without getting the same error now.

Solution 3: check the status of the Windows installation service

If there is a problem with the Windows Installation Service, it's natural to expect that any issue with it will affect any possible install or upgrade. Fortunately, it is quite easy to restart or repair a service and this is what makes this method very popular with users.

1. Open the Run dialog with the Windows key combination + R. Scribe “services.msc” without the quotes in the Run dialog box and click OK.

1. Search for Windows Installation Service, right click on them and select Properties.

2. Make sure the Startup Type option in Windows Store Services Properties is set to Automatic.

3. If the service stops (you can mark it right next to the service status message), you can start it immediately by clicking the start button.

You may receive the following error message when clicking Start:

“Windows could not start the Windows installation service on the local computer. Error 1079: the account specified for this service differs from the account specified for other services running in the same process.

If this happens, follow the instructions below to fix it.

1. Follow the steps 1 a 3 from the instructions above to open the Windows Update Service properties.

2. Navigate to the connection tab and click the Browser button …

1. In the frame “Enter the name of the object to select”, type the name of your computer and click Verify names and wait for the name to authenticate.

2. Click OK when done and type your administrator password in the Password box when prompted.

Note: Another useful thing you can do with the Windows Installation Service is to re-register it and see if that fixes the problem. This will also take a minute and may solve the problem.

1. Click on the start menu and type the following command into it before hitting Enter to run it:

% windir% system32msiexec / unregserver

1. Now you just have to repeat the same process only this time with the following command:

% windir% system32msiexec / regserver

1. Make sure to provide administrator permissions if prompted. Check if the problem with wula.exe still appears.

Solution 4: install the update manually

Unfortunately, It seems like sometimes the only way to really solve this problem is to take matters into your own hands and install the update manually if the automatic process just doesn't work for you.. Good luck! The installation process is a bit more complicated but it is nothing too complicated and you will end up with a completely updated PC.

1. Navigate to this page and find the latest servicing stack update for your version of Windows 7. The current version will be shown in bold. Make sure to install the updates from top to bottom and be patient for them to finish.

1. These updates are essential if you want to avoid the endless search for new updates on your computer., as these updates contain the updated version of the Update Agent, which means that you will not have problems with future updates.

2. Download the files to your computer, close all programs, run the files and follow the onscreen instructions to complete the update. Check if the update check was successful and if the error still appears “wusa.exe”.