Windows deletion is not secure enough. When you delete files in Windows by moving them into Recycle Bin all the data remain on your hard disk. You don't have to believe my words because you can make sure of it yourself. 

Try to search for some file recovery utilities. Such as R-Undelete or DIY DataRecovery. Then try to recover some file on your hard disk. An ancient information that your hard disk remembers will astonish you. And you can see all this because you did not use wiping. You just put files into Recycle Bin. Or press Shift + Delete on your keyboard. Try to wipe some file with QuickWiper or some other file shredders and then recover it.

Wiping is the process of overwriting the space where file located with some information. Different file wiping algorithms exists. Most file shredders allow to select which algorithm you would like to use.

QuickWiper is a file wipe utility.

Main benefits:

• File wipe utility and system cleaner. User-friendly privacy solution. 

• QuickWiper has integrated system cleaner 

• Can select any wiping mode: fast or most reliable 

• QuickWiper is a user-friendly program

• Lots of support information available

More topics:

Wipe files or folders

Wipe free disk space

Using system cleaner