System Update Readiness Tool for Windows 7 for x64-based Systems  947821
Windows updates and service packs could fail to install if there are some corruption errors on the user’s PC. For instance, an update might not install if there is a system file which is damaged. The DISM or System Update Readiness tool may help them to fix some Windows corruption errors.
Microsoft released this tool because an inconsistency was found in the Windows servicing store which may prevent the successful installation of future updates, service packs, and software. This tool checks a user’s computer for such inconsistencies and tries to resolve any issues if any are located.
Supported Operating System: Windows 7 Service Pack 1.