Every year, thousands of used laptops and hard drives change hands on eBay, OLX, and corporate disposal channels — with sensitive data still recoverable on them. A simple "format" or factory reset does not delete your files. It just removes the address labels. The actual data remains on the disk, fully recoverable with free tools anyone can download. For individuals, that means financial records and passwords at risk. For enterprises, it means regulatory violations, GDPR fines, and the kind of data breach headlines nobody wants. NIST Special Publication 800-88 — Guidelines for Media Sanitization — is the gold standard for solving this problem. Published by the US National Institute of Standards and Technology, it defines exactly what "securely wiped" means, and how to prove it. This guide explains the NIST 800-88 standard in plain language, covers the three sanitization methods it defines, and shows you how to apply them before selling or disposing of any storage device.…