If you cannot repair wusa.exe, you can still install Windows 7 updates manually:
Here is the correct workflow:
Websites offering individual .exe or .dll downloads are often untrustworthy. These files may be outdated, designed for a different Service Pack, or bundled with "injectors" that compromise your security. Instead, use the built-in Windows tools designed to repair itself. How to Restore wusa.exe Safely 1. Run the System File Checker (SFC) wusa.exe download windows 7