Only One Instance of Wusa.exe is Allowed to Run

Many of you must have encountered this error while using your computer. The ‘only one instance of wusa.exe is allowed to run’ is a type of Windows update error and is pretty common with the Windows 7 operating system. It may occur in different scenarios like updating Internet Explorer or even doing a standalone manual update of Windows. But don’t be alarmed as this can be fixed pretty easily. We’ll help you out with that. Read along. 

Solution 1: Perform the Windows Installer Check-up

The first way to solve the ‘Only one instance of wusa.exe allowed to run’ error is to check the Windows Installer service and see whether it’s updating the files automatically or not. Here are the steps to do so:

1. Click on the Start button and type Services.msc in it. 
2. Browse down the list and double click on the Windows Installer.
3. Once the Windows Installer tab opens, find the Startup type button. There change the option to Manual.
4. Then click Start placed right down below to start the service. 
5. Click on the OK button placed at the bottom to carry out the changes. 

Solution 2: Run your Task Manager

You can also fix the error by checking your task manager and making changes from there. Follow these below-mentioned steps:

1. Start Task Manager by clicking on Ctrl + Shift + Esc.
2. Go to the start task.
3. Start Wusa.exe. If the start task shows Wusa.exe as running, then end the process. 
4. Close the Task Manager.  

Solution 3:  Check your Event Log

You can also find a solution for the error from your event log. Follow these steps for it:

1. Go to the search box and click Event Viewer from the Programs list.
2. In the Event Viewer option, you’ll find Windows logs. Click to expand Windows logs and then proceed to setup. 
3. Then go to the Actions sections and click on Filter Current Log. 
4. You’ll find the Event sources list there. Click on that and find Wusa on the list. 
5. Then select the Wusa check box and click OK.
6. There you can find different instances of Wusa and find the cause behind the error. 

Solution 4: Reinstall Windows Installer in Safe Mode

The next solution is to boot your system into Safe Mode. Here you can click on the Advanced startup options and try to run the update. You can also try to disable your anti-virus software for the time being during the update.