A. 1. Use a disk cleanup tool to remove temporary files and remnants of uninstalled programs. Windows has a built-in Disk Cleanup tool that can be accessed by searching for 'Disk Cleanup' in the Start menu. 2. Manually search for leftover files in common directories such as Program Files, AppData, and the Registry Editor (be cautious when editing the registry).

B. 3. Consider using a dedicated cleaning tool like CCleaner to help identify and remove leftover files and registry entries. 4. Regularly perform maintenance on your system to prevent accumulation of unnecessary files.