Why am I unable to save my work under the File heading, I used to do this with my other computer.?

The save feature is there but doesn;t seem to be operational.Three quarters of the work I am doing is getting blown away by hitting a wrong key or some similar accident since I have been unable to use that save feature.I even tried to save it to a draft or folder and was unable to. I need help, can someone set me straight.Thanks is advance. I hope I am using this feature correctly, I didnt have this feature before.