How can you enter jpeg file descriptions and keywords in multiple files quickly?

I have about 200 photos of cars I photographed on a highway while I was driving. I want to embed keywords and descriptions in them without having to repeat the same actions for each file since the description and keywords are the same for all of them. Is there a photoshop or windows function or good freeware that lets you do this? I tried one freeware download that claimed to to this but it was as much work as typing in each file individually.