Before you pass on your old computer to another owner (donate it, sell it, etc) you should take great care to ensure that your private data has been properly deleted.
Unfortunately, deleting a file is not sufficient. Deleted files can be easily restored. Even formating a HD is not sufficient to ensure that you data cannot be recovered by someone else.
Deletion is not secure. When you delete a file the first letter of the filename in a directory entry is changed to a special character, but the file’s data remains on the disk. It may remain on the hard drive until it is overwritten by another file. And even in cases where your data has been overwritten, there are specialized program that can retrieve the information.
A recent study by a security firm has found that used HD that are being sold on ebay and other auction sites still contain sensitive user data that can be easily recovered. They have found tax returns, bank statement, private photographs, etc... In many cases, they even found company confidential information.
How can you ensure that your data in not compromised when you donate or sell your used computer?
WIndows users can use a program called QuickWiper to securely delete their data. QuickWiper is a file wipe utility with system cleaner. Use it to securely erase files from your hard disk. QuickWipe supports NSA erasure algorithm – data is overwritten seven times with “0” pattern then with “1” and so on. It is the best method for quick and secure deletion.
Before you sell you Windows PC to buy Apple's new dual core iMac make sure to run a utility like QuickWiper to ensure that your personal data is safely deleted.