This error most often points to a core problem with the Windows Update service itself. It may be stuck, hung, or its database corrupted.

When you download a Windows Update, it is not a simple file copy. Every official update package— .msu or .cab —is a digitally signed file. This digital signature is an encrypted stamp of authenticity from Microsoft. It serves two purposes:

: After the update is applied, it's recommended to restart your system to ensure all changes take effect.