Connection to Internet

I have a Compaq Presario 1200 series Laptom, and Iam using MSN. My question, sometimes when I get connected to the Internet, the bytes received and sent will just freeze up and I cannot search the WEB or even receive email, what is the problem, can you help me.

Also, sometimes connected at 14,000bps and sometimes at 44,000 pbs, and I get kicked off the internet before I can download email, who or what controls how long I can stay on the internet and be connected, the phone company, msn, etc.

Thank You
Bill

ps; Iam a Newbie