im not sure what the issue is…can you help?

i have setup a home network as below:

cable modem
|
cisco 2651XMrouter
|
cisco 3750 switch
|
PC1 Windows XP

from PC1 i can ping a internet address, but cant browse the internet. i think its a DNS issue, but dont know is this can be resolved with Windows settings….

please help…

thanks.