Color Picker issue: Photoshop CS6

[Gummo Marx]

Over the last few days, my Color Picker has imported a faded moon in the top-left quadrant and a black band at the bottom - any idea how to fix - please?

[Kevin Stohlmeyer]

@Gummo Marx check your monitor settings - Im not setting that on the supplied screen shot. It's not the software its your display.

[Gummo Marx]

Thanks Kevin.  I just checked - they're still the same as always.

[Gummo Marx · Accepted solution]

Success!!! I went into my Windows 7 Color Management and chanced adding the Adobe RGB (1998) profile and set it as default. My monitor had been appearing as the default.
The only puzzle now is how did Adobe RGB (1998) profile get deleted to cause this issue and I'm wondering had it been there as standard or had I added it years ago during a now forgotten drama.