Router/Hub Problem, 7 Computers

I live in a house with 7 computers connected to a router and hub. It appears that everyone only gets like 5 minutes at a time on the internet before it disconnects from their PC. I disconnected the Hub and we had 4 computers connected directly to the router with no Hub and it worked perfectly. The router does support hubs and switches with an Uplink button. We all have windows XP. My router is a "Network Everywhere" router. The Hub seems to be pretty old.

So I could use some help on what to do. Do you think a switch would do the trick or a different Hub? Thanks in advance.

Does this happen with only 1 hub connected PC turned on? It could be that collisions on the hub are causing connections to drop. I recommend getting a switch to replace the hub.