Hard reset on a dell c521

Does any1 know exactly what a hard reset will delete as I am selling computer so want to delete everythin put on the computer since I have had it. Dont wana delete windows xp or the microsoft packages etc....HELLLP!! Thanks xx

a hard reset will be where it reboots from a emergency disc and only programs on it will be uploaded. eg windows xp? other programs will need to be uploaded too such as office etc.
make sure all personal information is removed before getting rid of a pc as experts can find an amazing amount of info you thought you had erased.
ideally a full systems restore should be done to try and erase all data and files left on it before selling it .never a good idea to sell a pc without doing that or at least running a disc erasing program designed to wipe all disc clean as a new pin.
pain it will be reloading software but do realise it may need doing and it should need regeresting as a new user when sold by purchaser . ( the often don't bother)
hope all goes well for you.