Why does my computer keep freezing up?

My computer, mouse, keyboard keeps freezing up so nothing works, when I am on the internet. I have a satellite connection through ihug, but I have to connect through the modem with ihug and then the satellite connection is supposed to take over.
Atthe moment, I can connect through ihug, but can’t get the satellite connection to work, despite talking to ihug tech. helpers. Everything seems to be set up correctly but still no satellite. Even got them to send me a new card to instal. Same result. Why does the system keep freezing up when I’m connected to the net?