Internet wont work all the time?

Hello,
My name is Colten, and when i'm on the internet, it says I have 5 bars so I should have a good connection but most of the time i'm on it wont take long before it says "Internet Exlorer cannot dislay this webpage" and it takes a long time to load to the next page. It does this most of the time. Sometimes I can browse for a little awhile but usually I have problems with the internet working properly. When I use someone elses wifi (like my parents house) the connection is good and the internet is fast and everything works great with 2 laptops and 2 xbox lives going. but at my place it has a lot of trouble. I dont know what the difference is. I will say there are two xbox lives hooked with it along with a possible of three laptops all going at the same time ( I dont know if that means anything?) but I am not able to be on the internet for a long time if at all without the cannot display page coming up. It says network availability: All users so im confused on whats going on. I have comcast and belkin.4D65. So I have no idea why my internet doesnt work good when its displaying 5 bars? If you could help me on this problem or let me know on what needs to be done to fix this, I would apreciate it. Hope to get a response soon. Thank you.