yes you do not need an operating system on the drive to erase the data on it. What youll want to do is format the hard drive, which can be done with a windows cd.
Do you have a OS installed? if so, how big is the HDD? If its at least 3Gb, you hshould be fine. Just strqat uninstalling programs. Or put your HDD in a dif PC, and then format it.