The 'Brightness/Contrast' dialogue screen becomes unexplainably absent in PhotoShop 7.0 on XP

About every year of so the 'Brightness/Contrast' screen becomes unexplainably absent while using my PhotoShop 7.0 in XP. When I click on 'Brightness/Contrast' the eyedropper becomes active as usual but the dialog screen with the two 'sliders' for brightness and contrast is not visible. Where is it? If I uninstall and reinstall it's OK again for a while.
Bob Arens

It's not unheard of for dialogs to become lost off screen. It can happen when you reconfigure your display rez, or rearrange monitors.

Before you re-install (assuming this happens again), try resetting your prefs by pressing the ctrl-alt-shift keys during startup.