IS there a way of removing a prefs/setting (screen resolution) with out re-installing amigaos. (win uae). ?
Of course. You can fix _everything_ in AmigaOS without re-installing it. It's some weird bad habit from the Windows world (I assume) to re-install the OS even with small issues.
BTW. My base installation of my monster A1200/everything/uptodate is still the original from 1993 when I got it.