Problems with my internet

So lately, my whole family has been having problems with our internet stability. We'll be all fine for about, say, 5 minutes. Then, randomly, pages suddenly go to the "Error, Unable to Connect" crap. So you refresh it like 6 times, and it is back. You move to another page, and it disconnects again. Then after about 10 minutes of that, you can go free again for about 5 minutes, and the process starts all over again.

We think it may be our ISP that's causing it, but we're not entirely sure. Anybody know what the problem might be?