Can't install Source Filmmaker.

Okay,so,i logged into steam today,went to play some Killing Floor and BAM. there's a extra game there uninstalled. It's the source film-maker. I'd applied before,but i doubt i would have got it.

I crapped myself.

But i can't seem to install it. It starts the install then gives me : 'An error occured while Installing Source Filmmaker (Connection timeout) the connection is a bit jumpy for me at the moment,but how can i fix this?