Just boot up computer with the Win2000 CD inserted (making sure in BIOS, CDROM comes before hard disk in boot priority). When you get to the Win2000 Setup welcome screen, press Enter to enter setup, F8 to accept agreement. If asked, always choose to install a fresh copy of win2000.
When asked where to install win2000, highlight C, press Enter. When warned about Windows being already on C, confirm that's what you want to do. When given formatting options, choose Format with NTFS file system. Wait for it to finish. Files will then be copied to the hard disk. Computer will need to restart. Let it do so, and leave win2000 CD in, but this time, do NOT boot from CD. Just let computer boot from hard disk. Then follow the prompts.