linksys wag 54 cant conect to the internet

ive got a problem with my router which is connected via ethernet cable to pc1 pc 2 has a wireless net work card i can see my linksys connection and when i connect i can use print functions on pc1 and access shared files on pc1 but i cant connect to the internet.and when ive used the cmd command its is saying incorrect domain,im not to hot on networks this must be some setting ive not got quiet right i would be glad of any help in this and so would my son.ps both pc,s run on windows home edition with service pack 2