I recently tried to download and install a few Windows 7 updates, but the auto-updater kept aborting the process with the error number “8007051a”. There was no particularly descriptive error message. At first I thought that it was just some server that could not be reached. But when it still didn’t work after days, I began to investigate and found a solution in the Microsoft forums.

The problem is apparently caused by faulty system files. To find and repair them, there is the System File Checker (sfc.exe). And here’s how you use it:

1. Start Menu → “All Programs” → “Accessories” → right click “Command Prompt” → “Run as administrator”. Should you be prompted for an administrator password or a simple confirmation, type in the password or click “Allow”.
2. At the command prompt, type the following command and press “Enter”:
   sfc /scannow

The program will now scan all system files and replace incorrect versions with the correct ones from Microsoft. After that, the automatic update should be working again.