Windows Update Error Code 80070663 typically occurs when installing .NET Framework updates or during cumulative Windows updates, often due to corrupted update files, interrupted downloads, or security software interference.

To resolve this issue, begin by temporarily disabling your antivirus and firewall so that the update process is not blocked. Next, reset Windows Update components: open Command Prompt as administrator and execute the following commands one by one:

Once the services are reset, repair system files by running sfc /scannow followed by DISM /Online /Cleanup-Image /RestoreHealth to fix any system corruption that may be triggering the error.

After these steps, restart your computer and initiate Windows Update again. If the issue persists, download the failed update manually from the Microsoft Update Catalog, or install the .NET Framework update directly through Control Panel → Programs and Features → Turn Windows features on or off.

For a complete, detailed guide on how to fix Error Code 80070663, follow the walkthrough provided by WinChatSupport.