That's obviously Windows on there. What version of OS X/macOS was on there before? Do you have a backup?
Also, not iOS, so this is in the wrong forum. Might get better help in the proper forum.
I think he understood your problem. He probably meant that this area of the forum is used for iPhone/iPad software related questions. Since your problem is a missing / deleted operating system the question should have been posted in the macOS section to possibly get more answers. Don't worry about that I moved it to a more appropriate area.did you not understand that's mac boot via windows my stupid brother do that so.that's why i here need help for that can you?