How do I and is it undamaging to......?

I have an old Gateway Computer and I own bought a new computer to replace it, and near the old one I have an External 40gb HD. I want to Reformat the External HD and take ALL the folders and such out of it so it will merely be like it be when I bought it with nought on it. It is NTFS formatted, and I do not need any of the files anymore and it is a moment ago taking up free space and I want to clean everything out of it. Hope you twig what I am saying. I am moderately new to computers and do not want to mess the External HD up as it is correctly new, and I sure do not want to mess up my exotic computer I just bought. My unsullied computer is a desktop NTFS formatted. Please help if you can. Thanks to adjectives.

How do I and is it undamaging to......?

The simplest way would be to hook it up to your brand new computer and look in My Computer for the deity for the drive (D: or which ever one it is.) and then right click on it and choose the format selection. It will format the drive and then it will be meaningless. There are other slightly more exotic ways to clear it also but since you say that you are moderately new to computers, they would probably be more hassle afterwards help.

Good Luck beside your drive.
hook it to your new computer,it will be allocated a memorandum.go to my computer,right click on the drive,formatt using ntfs.