Whenever selling a computer of a hard drive you should ALWAYS wipe the drive clean with a Eraser program to prevent any personal data from being recovered and used for identity theft or theft of bank info, etc. Here in the USA the government standard is to erase and overwrite the same sector a minimum of 7 times. I had an Eraser program on my laptop that would erase the recycle Bin with 5 - 32 passes each time you wanted to erase anything in the Bin.