Internet Problems

[Xodus]

my internet is only letting me on msn,yahoo. and it wont goto webpages or let me play games due to the rediculous ping i get. i got Cable 3.4meg. Sometimes i can veiw websites and sometimes it says page cannot be displayed or i get a msg saying internet explorer cannot open the search page =/. all of a sudden al this happened after a format, could it be my ISP? or something with my computer? like right now i can goto websites, then its gonna cut me from it. heeeeeeelp