Before you reinstall, on a long shot, if you right-click in the workspace, before you open a new window or project, it might give you the option to "Show Windows" or CTRL+SHIFT+F4. You might give that a try.
As per my previous post, I think you might have misunderstood. By taskbar, I mean the windows taskbar at the bottom of your screen. It lists all the open programs, I was currious if you clicked on that icon for Corel Photo-Paint if you had any options to restore, minimize or maximize. These options should be independent of what is displayed on the Corel traskbars.