WinSysClean is safe, it uses complex analysis to skip important data from removal.
Other tools puts all the responsibility on you, they ask you what to delete and what not, which takes you time and sometimes they make your demolish your Windows.
Automatically Optimize your Windows System:
WinSysCleanautomatically optimizes your Windows System by optionally removing temporary/unused space wasting files, unused and invalid registry locations, invalid shortcut links, and many more, works with Windows 10, Windows Vista, Windows 7 and Windows 8. Uses the most complex registry analysis algorithm in order to repair the Windows Registry. This version includes 84 cleaning and repairing operations.