Thank you for your kind reply's suggestion, but I tried that already and the checkmark for , still is seen when right clicking the desktop's lower right corner icon (next tto the clock).
It seems that regardless that I've turned off aero, unghosting the tick box and unticking it, Windows 7 seems to be determined to re-tick it.
I'm left believing that this is one of thise things like when users don't want to use WMP and 'we' untick WMP from add-remove programs list, many file xtns still display the WMP icon ,as well as the default programs list still lists WMP as an option, ie; 'nag-ware'.