Windows 10: Update error 0x800f0900

I cannot update both .NET version 3.5 and Windows Update KB4556799 and also an update to version 1909 due to an error0x800f0900. An SFC scan found some corrupt files by the CBS.log file the file seems to be "dpnet.dll", as shown in the embedded image, but was unable to fix them.

I tried to replace those files with version I found on the internet both in system32 and sysWOW64 as I have 64bit Windows with no effect. I also tried fixing them with the DISM RestoreHealth function, also without success. I also tried to install the update manually by downloading it from the update catalog, unsuccessfully.

Does anybody know how to fix the issue ?

:)

 

Windows update fails with Error 0x800f0900

Unable to install both latest cumulative updates.

The installation of 2019-04 Cumulative Update for Windows 10 Version 1803 for x64-based Systems (KB4493437) failed yesterday with Error 0x800f0900 and today the installation of 2019-05 Cumulative Update for Windows 10 Version 1803 for x64-based Systems (KB4499167)
failed too with same Error 0x800f0900.

I ran the Troubleshoot app on Windows Update. It fixed Service registration missing or corrupt. However, running Windows update still failed with same Error 0x800f0900.

Restarted the computer several times and search the internet for fixes without success.

Please help. Thanks, Blaise

 

cant fix error 0x800f0900

trying to update to version 1803 and keep getting error 0x800f0900.

 

Feature Update to Windows 10, Version 1803 - Error 0x800f0900

OK.
I have been informed by a reliable source that the reason I cannot update to 1803 is because I have no System Reserved Partition. See image below.

What's the best method for me to create one? Also, I have read a number of articles that suggest to make it at least 500 MB, instead of the standard 100 MB.