internet browsers start to load webpages slow

hi

i beginning to have a problem with loading webpages
they are starting to load slow and its beginning to be even slower

at first i tough that maybe it was the browers but now i tried IE9 chrome
and i already used firefox

and they all have the slow down problem

the problem is i have no idea where to look for this problem
but the slow down starts to be a big problem

thats why this post i really hope someone can help me