Computers often hold personal and financial information, including:
•license keys or registration numbers for software programs
•addresses and phone numbers
•medical and prescription information
•files created automatically by browsers and operating systems
When you save a file, especially a large one, it is scattered around the hard drive in bits and pieces. When you open a file, the hard drive gathers the bits and pieces and reconstructs them.
When you delete a file, the links to reconstruct the file disappear. But the bits and pieces of the deleted file stay on your computer until they’re overwritten, and they can be retrieved with a data recovery program. To remove data from a hard drive permanently, the hard drive needs to be wiped clean.
How to Clean a Hard Drive
Before you clean a hard drive, save the files you want to keep to:
•a USB drive
•an external hard drive
•a new computer
Check your owner’s manual, the manufacturer’s website, or its customer support service for information on how to save data and transfer it to a new computer.
Utility programs to wipe a hard drive are available both online and in stores where computers are sold. These programs generally are inexpensive; some are available on the internet for free. These programs vary:
•Some erase the entire disk, while others allow you to select files or folders to erase.
•Some overwrite or wipe the hard drive many times, while others overwrite it only once.
Consider using a program that overwrites or wipes the hard drive many times; otherwise, the deleted information could be retrieved. Or remove the hard drive, and physically destroy it.
If you use your home or personal computer for business purposes, check with your employer about how to manage the information on your computer that’s business-related. The law requires businesses to follow data security and disposal requirements for certain information that’s related to customers.