Computer safe mode

[dios]

today when i turned my computer on something wierd happend,
when i turn it on the screen has like faded white stripes running down it and i have to use the safe mode option to go onto my computer,

*edit*
160G samsung SATA II hard-drive
Abit AW8MAX-3RDEYE Mother-board
ASUS Extream N6600GT Graphics card

[GX1_Man]

Perhaps some info on the hardware would be helpful? See below.