cannot connect to internet

Please help. I am computer illiterate. I had this problem before and came here, found help and all was great. My problem - I was on the internet checking my e-mail, tried to delete the e-mail and got kicked off. Now I am unable to reconnect. Checked settings and all is good. I was able to come here, but cannot get to yahoo, google or anywhere else. My system restore was off. I have a Dell computer and use Windows XP. My internet service is Charter DSL.