and plan to keep Windows 98 on it, you will HAVE to send the installation disks along with it since the operating system doesn't belong to you.....the license to USE it is all you pay for. So....either format the drive and leave it empty for the next person to put their OWN copy of windows on it, or give up the installation disk.
That said......the easiest method to do what you want is to format the whole drive and reinstall windows from scratch on it. That will also wipe out any passwords windows saved from the internet. Just deleting files and then overwriting them with another program to erase the stuff for good will be a long, time-consuming process as you pick and choose what you want to leave behind.....and even that will leave you as listed as the registered owner with much private stuff still in the registry that will have to picked apart.
How can I permanently erase data from the hard drive on a computer without erasing the Operating System (Windows 98) so that it can still be booted up? I want to be able to donate the computer.