CCleaner ???????????

[looked]

Reboot the system Before the change to any critical setting, (to ensure the system is working correctly before you change anything), Make a single change, Reboot the system to check that it still works correctly. This takes longer than the "Silver Bullet" but is less likely to ruin a system and potentially create losses of time and money

To avoid problems I always have installed a way back machine like for example the free edition of Rollback so if anything goes bad, I'll simply reboot and reload a previous working image.

 

[Barman58]

Thats a good method as long as the system has been kept active by the user
My method is what I try to work with However ...

When you have the company owner standing behind you and the downtime is costing thousands of Pounds a minute, and an unknown recipe change in the, (Badly documented), product software, that has not been saved, is the cause of the failure you make your own latest backups and check them before you act - you then try to solve the issue without loosing the unsaved data

 

[RoasterMen]

You should really be careful if you're going to clean unused registry files with CCleaner. The program will even warn you about it.