My ADE 4.5.8 works but I cannot make it full size

I have deleted and reinstalled my ADE, currently version 4.5.8, and it works perfectly: I can see the miniature window when I move my mouse to the ADE symbol in the taskbar, BUT it will NOT go full size. It is the only program I have with this problem: all other programs go full size when I click on them in the taskbar. So how can I make ADE go full size, so that I can actually see it properly?