PC hardware: Hard drive cleanup

Are you saying you want all data removed?

If so, there are several ways from simple to complicated to get this done. It will depend on how sensitive you think the data is and what you intend to do with the drive. If you're going to sell or donate it and the data isn't that sensitive, you can just delete the partitions with simple utilities such as fdisk. If you want the actual ones and zeros to be gone, you should look for the drive manufacturer's diagnostics utility that will erase the drive. This does an adequate job for most purposes but doesn't mean the residual magnetism held in the media cannot be read by very sophisticated equipment designed to do so. If you're data is of Top Secret government importance, there are stronger 3rd party utilities that can give it a good scrubbing. If you're going to sell or donate the machine, there is always the option of doing so with no hard drive included. In this case, some good sledge hammer or pick ax swings to the drive in the right places will render it unreadable.