windows- display settings , help

[polaris]

hello all
ive been trying to adjust my windows (xp) to run mame 32 a bit nicer on a tv through a scan converter.
when i first adjusted the resolution of my desktop ,i was given 2 options 800x600 and 1024 x768 ,i swapped to 800x600 and had an effect.
but on resetting to the standard monitor resolution the toolbar at the bottom and my favourites stayed in the 800x600 display size.
reopened properties and it gave me more resolution options than before ,higher no's ,(still no 600x 400) but going up to 2000 x something.
still parts of the screen are at different resolutions.
any clues?
sorry if its badly described
cheers