Try not moving them in there, move them into your project's chipset folder. You have to look on your desktop>C>Program Files> (either Enterbrain or rpg2003)>Projects.
That's onyl if you saved it in the default folder. Or else you'll have to do a bit of searching.
Or just install rpg maker 2000 rtp, and then import the files through rpg maker 2003 into your project. The RTP's default install folder is My Computer/C/Program Files/ASCII/Rpg 2000/RTP/Chipset.