I need help with my Internet Connection?

[jivepacketrat]

If your laptop works and your desktop does not, then check the configuration for the laptop and note any differences with the configuration for the desktop. That includes making sure that the desktop uses autonegotiation for both speed and duplex. If your laptop and your desktop has different settings, that means that the modem has the same as the settings as the laptop. If you connect a device that has autonegotiation, to a device that has the speed and duplex configured, the connection will work fine, will work intermittently, will work only occasionally, will not work at all, or will randomly do all of the previous. If you use a command window, and type ipconfig /all, when it is working and when it is not, may also give you an idea of the problem. Too many questions to solve to write them all here.
It is possible that when "your Internet connection works", that you are seeing cached pages and not actual pages from the Internet, so your connection does not really work. If unsure go to a site that you have never visited.