RECOMMENDED: Click here to fix Windows errors and optimize system performance
Error 0x800f0826 usually prevents the installation of Windows 7 Service Pack (SP) 1. The system usually downloads and installs Service Pack SP1, but returns to the previous version of Windows because of this error. The error is displayed, whether you are installing Service Pack SP1 from Windows Updates or from the standalone installation program.
There are several ways to solve this problem.
Restore deleted drivers
Since the problem is mainly caused by the driver cleaning tool you have used in the past, using the same tool to restore these drivers solves the problem. Generally, these driver cleaning tools have a backup copy that you can use to restore your drivers.
Go to the official page of the driver cleaning tool you are using and look for the information you need to recover the deleted drivers. You can use their website, browse their forums or contact them to obtain this information.
Once you have restored the drivers, try reinstalling the Service Pack and the problem should be fixed.
If, for any reason, you cannot recover the deleted drivers, you can still download the new copy of these drivers from your official website.
Clean Install windows
Your best choice for machines that have failed is to reinstall Windows 7, then install SP1 before any other installation. Once the Windows 7/2008 R2 SP1 installer fails, it tends to damage various parts of the system. When installing SP1, also make sure that all other installations are complete and that no other updates are performed at the same time.
1. Terminate the Internet connection.
2. Disabled the antivirus and firewall features and everything else I could find – basically the whole McAfee suite.
3. That was the problem: In Services (as administrator), I right-clicked on “Windows Modules Installer” and on Properties. On the Restoration tab, the original settings were First failure – Restart service, Second failure – Restart service, Subsequent failures: No action taken. What I did was change the Subsequent Errors parameter to restart the service. This was entirely a guess on my part, but I thought that if the problem was that WMI did not remain automatic, then the service could stop during installation. I was hoping that this would force a restart. Well, I may blow smoke on this case, but it worked.
I hope it will work for you. Let us know in the comments below.
RECOMMENDED: Click here to troubleshoot Windows errors and optimize system performance