Resize it from the top to make it smaller, then drag it up.
I'd also try toggling through the screen modes with the F key, and if the image window is floating, I'd drag to the top of the screen till you see the blue highlight, and release to 'tab' the image to the Options bar. Or if you can access the menus, go Window > Arrange > Consolidate all to tabs. You could then zoom back with Ctrl Mouse wheel, or whatever your preferred method is.
Or if the image is floating, it is worth hitting the restore icon in the top right corner
Is it fixed now, Deborah?
This has happened to me a number of times.
Move the top of your work space down until you can see a gap at the top. Then hover over the very top of the workspace and you will get a double arrow symbol pointing up and down.
Click and drag it down to reduce you windows height. Next pull your whole work space up and repeat this process until the workspace is no longer going off the bottom.
You can use the same method to reduce the width also.
Thank you, this is so simple and Handy to know.
Thank you so much! this was driving my crazing - all fixed!