Is there a tool that will check integrity of system files in Win7 and search for invalid or changed ones. I would like to find which files were changed by rootkit installed on system. It would be nice if there existed some databases with system files names and corresponding hashes (original and updated by Windows Update).
This command (System File Checker) scans the integrity of all protected Windows 7 system files and replaces incorrect corrupted, changed, or damaged versions with the correct versions if possible.
You can read this tutorial on how to use it: