Why won't my computer connect to the Internet

Hello,

OK, so i just purchased a new laptop and have to connect it to the internet. Bought a router, installed it and hooked it all up, my laptop detects internet fine and works dandy. Only problem is, that my desktop computer that connected to a wired modem, which now has the NEW router connected to it, will not detect the internet connection.

After installing the cd and followed all the instructions, it appears we have all the cords in the right place.... here is what we did:

1) Took the existing ethernet cable from the computer and plugged it into the port labeled "internet| on the back of the router.

2) Connected one end of the supplied ethernet cable to port 1 on the router. connected the other end to the computer.

3) plugged in the router to an outlet.

4) followed onscreen instructions to finish the setup process.

Following this, i checked my laptop, it found the network and connects to it great. Tried to go online on the home desktop and it will not connect. When i try to connect, it says the following:

"Error 678:
The remote computer did not respond. For further assistance, click more info or search Help and Support Centre for this error number."

Any suggestions or help is greatly appreciated!!!!
Thanks for your help!

PS- I pretty much copied the steps i took from the instruction manual, so please don't say that they are hard to follow or vague- they were what I was given!

Configuration: Windows Vista (laptop) & Windows XP (desktop)
Firefox 3.0.3