Seagate hard drive

something like this--though you could get a larger size if you wanted

http://www.ebuyer.com/272944-seagate-500gb-barracuda-in...

What you're looking for is an internal hard disk drive (hdd), you get to choose "How big", "How fast", and "How much you want to spend"

Western Digital Blues are usually a good balance of speed and reliability.
Heres a list of drives sorted by reliability ratings on Newegg
http://www.newegg.com/Product/ProductList.aspx?Submit=E...

just to clarify that a little

you want an internal hard disk drive--thats sata not ide

though probably not many places selling ide ones nowadays but wouldnt want you to accidentally get an

ide one

and they go up to 4tb now

but i would think if you go over 2tb you will have problems booting from it

also do you have recovery media to install windows to a new hard drive?