when i call up the colour picker i now have a gradient of green to blue instead of the white in top left, red in top right and black at the bottom. i have selected default colours and checked other settings from another pc but no luck. the vertical bar does not cover the whole spectrum as before either

Iain.

Check again the other PC's color picker very carefully : notice that the radio button in front of "H" is populated. ;D

thank you so much, i never gave it a thought it may have been on hue. naturally assumed it should be on rgb

iain