Help! i need help about my computer?

i was on google video and a warning popped up saying 178 adult websites were visited and like 100 illegal sites. it alosaid something about i could be i jeopardy of losing my job and marriage. it also gave a list of the sites visited. i have looked at in the past but someof these sites i would have never visited. i tried to delete history but now i fear it isnt deleted. does anyone know how to once and for all delte these sites and does anyone know of the warning im talkin about? if iut ever happened to you how did you deal with it?