Excel screen size has shrunk and is unable to maximise the same. The minimise and maximise tabs are missing

[sachuolessa]

Excel screen size has shrunk and is unable to maximise the same. The minimise and maximise tabs are missing

 

[Special-K99]

Windows?

Try going to the Windows status bar at the bottom of the screen.
Hover your mouse over the Excel icon until an image of the Excel screen appears, right click and you should get the maximise option come up.