I got myself into a similar problem once. Even worse, I had it working and then re-installed Windows and it quit! What I failed to realize was that I needed to install the device drivers for the mobo - they all came on a CD with the mobo. Among other devices without drivers were the on-board network port drivers. Have you installed your mobo's drivers from its disk? Do this before trying to install software that came with the modem and router.
I tried to but after the first Rebbot of 3 required the PC loaded up to the DOS screen and gave me three options to choose from a, b or c. A and B were to create a 32bit or 64 bit floppy disk. C was to skip and go to the "C:" DOS screen. I don't have a floppy drive on my new machine. I didn't think I would ever need one. And I didn't know how to get from MSDOS Command back into windows to continue the process. If that's even possible. So I just restarted the PC, "Deleted" into the BIOS and reset back to factory settings so that whatever was installed from the disk prior to reboot 1 was turned off so I could get back up and running. I figured the Mobo Support DVD was optional. If it isn't then I better get over the Mobo forum for help.
I have not installed any device drivers for the Mobo.
If anyone else has a comment feel free to give me any insight.