Rather than deleting existing data, and wondering whether you've got everything, wiping any drive that you plan to give to someone else will insure that no sensitive information or data files remain. Here are the steps to accomplish that task.
Save any important data on the unit to external media such as a USB flash drive, external hard drive, etc.
Download DBAN from:
Create the necessary media.
Find and download *all* the most current versions of the necessary system drivers, SATA, BIOS, etc.
If the manufacturer has any specs on a proper install order for drivers, find them and print out a copy of that article.
If you haven't already, upgrade the system's BIOS to the most current version.
Boot to the media onto which you have burned DBAN. At the prompt, type AUTONUKE. Press Enter. Take a break until you see the black screen that indicates the disk wipe has completed.
If you are only donating, you are done at this point. If you are giving it to someone you know, or selling it, continue to the end of this article.
Boot to your OS media and install the OS.
Once the OS has been installed, follow the steps in proper install order for drivers article and install the drivers in that order.
Once you have network connectivity, go to
Do a Custom install of the necessary OS updates. This will allow you to see what you'll be getting and opt out of any updates you don't want.
Once this is done, reinstall any additional software you want to include. Update it as necessary.
You are now ready to hand-off the device to its new owner.