Is this a brand new PC or a second hand PC ?
Has Router/modem connected to internet with other PC's ?
(If second hand and previously used on a corporate network you may need to carry out a complete re install of Windows to remove lock down of Windows configuration)
If you plug a network cable into network port on PC and into your Router Modem it will try and connect to the internet and after a short delay ask you for network locationhttp://windows.microsoft.com/en-US/windows7/Choosing-a-network-location
then PC will be ready to work on internet and will probably start downloading Microsoft updates for several hours
(best to let this finish before browsing internet)
(note most internet router modems (via telecom lines) need a user account name and password when first installed, though some are pre configured by ISP before delivery.)