How to add keywords to the file?

[mentos_007]

Ok I know it's obvious to right clik and add keywords in file properies. But is there any other way? I mean when I added some keywords with a method I described above, and I sent the file. And my "boss" told me that there are NO keywords... I don't know why. When he sent the file back (it's a photo) and told that he added some keywords I couldn't see his keywords only mine that I added... What's wrong? Or what am I doing wrong?