Clean Up Second Hand Laptop

I have the opportunity to replace my old laptop with a good used one. It belongs to my son and has been used only for business purposes. My problem is that it is quite full of old files containing unwanted jargon. what would be my best way to clean out this machine without restoring it to default?

 

Firstly, delete all the files on it not needed in the normal way - make sure you do it signed into a Administrator user account. Uninstall any software you don't need - use something like Revo Uninstaller (choose the 'free version' download link) and select the 'advanced mode' for thorough uninstall.
Restart the system, then run CCleaner Slim and run its 'Cleaner', then run 'Registry > Scan > Fix all issues
Now use the 'wipe free space' option in CCleaner > Tools > Drive Wiper > choose each drive one at a time (but only if it has more than one drive). If you want the free drive space wiped so clean the deleted data cannot be recovered then set the options to at least 3 passes.
Once that's done you're good to go.

 

Thanks a lot, Max. Most helpful

 

You're welcome