Hello, can you upgrade to a larger hd without needing software
More aboutfujitsu siemens lifebook c1320
You'll need the OS installation disk(s), as well as any driver/programs/etc. installation media. All of these should have been included with the computer at purchase.
Or you could clone the existing hdd to your new one. But since you asked the question I'd suggest you get someone more tech savvy to do this for you. It saves you a lot of trouble if you have a lot of stuff on it.