Erase a Disk in Windows 10 is easier than in Windows 7, the newest Windows System added a function to remove everything in the default tool. Here are the steps to wipe everything in Windows 10 default settings:
If the following message shows: make sure you had inserted the bootable CD.
Could not find the recovery environment
Insert your Windows installation or recovery media, and restart your PC with the media
Erase Disk Partition in Windows 10 using Command Prompt, here is the guide on how to erase data partition in Windows 10 using command prompt:
This is for wipe data partition, not local disk C, system partition, check here to see how to wipe system partition using command prompt.
Erase Disk in Windows Default settings or using Command prompt both requires bootable CD when you want to erase the whole disk with OS in, can we erase everything without a bootable Disc or USB?
Macrorit Disk Partition Wiper can erase everything on a disk including Windows itself even when Windows is running; no bootable Disc or USB is needed. Here're the steps
After this, the Disk becomes uninitialized, RAW disk with factory settings, now you can feel safe to let it go or give it away.