my hard drive is getting replaced tomorrow and I was wondering about my personal data when they remove the old drive, like passwords and card details old email, Should I be doing something ? I got A 2000:0142 Error and my laptop was under Warranty so dell are sending somebody to my home to replace the drive, Dose anybody know what you should do to ensure your personal data keeps safe.
If the drive is still accessible, you can use a utility to wipe it clean (lookup DBAN).
If it's not readable, the only sure way to safeguard your data is to destroy the drive yourself - which means you'd need to buy a replacement drive yourself -- if you have it replaced under warranty you must surrender the original drive.
In addition to what Ejn63 has said, you may also contact Drive Savers and get your data backed up.
Hope this helps!