Hi I have X4 currently and got an email about X5 do I just download the newer version and my old serial number will work or not. Also how do you get the menu bar back on top of the program.
X4 and X5 are completely independent programs; X5 is not an upgrade you can just freely download, you have to buy it! (There is a time-limited trial version you can download for free.) Once bought and installed you will find it and X4 both listed in your computer's programs.
You cannot use your X4 serial number to activate X5. The act of "buying" the new version will give you a new serial number specifically for X5.
As for the question about the menu bar, have you tried Window>Window Arrangement>Default? Or is the bar that includes "File", "Edit" etc. the one that you are missing? In which case, try F9, which is the shortcut for "Reset Window Arrangement".