I need help with what I am sure is an easy fix....

I recently bought a computer from a friend. (My old one was dying a slow death and was so old that it could only use dial up! ) So this new one is wonderful, but I am not very computer savvy. I have my dsl up and running, but not all pictures/logos show when theyshould.

For instance, my PT logo only shows as a red X, same with the reply, edit, etc. buttons. Some members signatures show, others don't. I have the same problem with parts of other sites that I go to..... including google!

I am certain I need to download something, but I have no idea what.

Can someone please help me? I miss the PT logo!