Page 1 of Display probs after safe boot

booted today after normal shutdown to be booted into safe mode. Did a scandisk and the 2 things it fixed were incorrect times in my hotmail account. Fine I thought, but booting normally display is frazzled. Was in 16 colours and size 640 by 480 and set as display large fonts. Changed clouors back to 256 with no probs but cant change screen size( dont really need to) but cant uncheck the box use large fonts. When I do it reverts back.....any ideas this happens too often!!!Thanks in advance