Have researched this and found good answers. But my question here is can you turn that pop-up message "The monitor profile "Samsung - Natural Color Pro 1.0 ICM" appears to be defective. Please rerun your monitor calibration software" on and off.
I may have checked the "don't show this message again" ??
If so...can I re-enable the the profile warning message and how ?
Or...does this pop-up only occur if there is a monitor profile issue when Photoshop starts ?
Adobe Photoshop CS4 (64 Bit)
The question is what alternative you picked before you checked "don't show". The options are "use anyway" and "discard" - and in the latter case sRGB is used instead.
The Samsung profile is very likely defective (many canned profiles are), so you're better off using sRGB unless you have a wide gamut monitor.
To correct the problem permanently you buy a calibrator to make a new monitor profile. Then it's moot.
EDIT: There is a Reset All Warning Dialogs in Preferences, to answer your question.