I want to add my printer to my computer but need to download something to be able to do it as I don't have the instalation disk... its an epson c40ux... can you help?

You are probably needing driver's for that printer. You can find much of what you are needing online. Google that model number and look for updates and driver's. They should be very available.

What version of windows are you using, this link should help you out
Epson Stylus C40UX, Drivers & Downloads - Technical Support - Epson America, Inc.

Post back if you run into a problem