Lost CD-ROM

Upgraded Win98SE to Win2000 - no problems except for no onboard sound.
Installed SP4 - no problems.
Looked for sound drivers -installed sound, but LOST CD-ROM drive
(CD ROM recognized in BIOS).
Removed CD-ROM hardware and software- reboot/shutdown. Connected CD ROM
- BIOS recognizes, Win 2000 does not.
Repeat with another CD ROM drive - BIOS OK, Win 2000 no CD ROM.
Looks like Win 2000 problem, but how can I reinstall Win 2000 without
CD-ROM?
Tried 4 floppy disk Win 2000 setup, but got "Stop Error."
How do I even re-format C drive - it's in NTFS file format.
Please help me with my total frustration.