Wonder why you want to do this?You do need to get a memory card reader for a start.
If the photos are on a CD then the sequence would be to put CD in drive ,go "my Computer ,then your CD drive Right click on the CD drive,scroll to explore,identify the photos,highlight them,right click on them and drag to desk top.Select the option "copy here"
If they are already in your computer the above step isn't needed.
Connect your card reader to a USB port.If you are running XP or later the computer will auto instal the reader.Plug in th memory card into the reader.It will show as a removable drive in "my computer"
Locate the photofiles ,highlight them,drag and drop the highlighted files to the drive .
However,in my experience cameras are not very good at reading files put on a card in this way,so although you will have copies on the card your and other computers can read suspect they won't display on the camera