with code or no code, baud rate of 38400 is not listed in drop down menu?

odd - in the serial monitor window, with the drop down menu, the Uno does show the baud rate of 38400 on one computer, but doesn't on another, it skips it (and probably a few others)...it doesn't matter if it is written into the code to be uploaded or not. In Windows, the port is set up to be a 38400 Baud Rate, but the arduino program, like I said, just does not have it listed? This only occurs on one computer, on another it is listed, so it is not a card issue?

Which operating system your using. In how many system you been tried. Which version of arduino You downloaded,