Unstable internet connection

I have intermittent connectivity when my satilite modem is directly plugged to the computer and no connectivity if I attach it through a router. Troubleshooting through router provider and internet server both working well and point to the network driver as the problem. Dell wants to charge 200+ for seeking out the problem as they say it is a software issue. I just layed out 2000+ on this new computer to have this problem.
What do you suggest?

I doubt its a driver issue, it sounds more like Win 7's default network settings are incorrect for your setup. I do not use a satelite modem nor have I ever, so I can't speak on what settings it needs, I did notice however that when I installed Win7 it auto setup the network, which is working, but in xp I had to change the settings from the default. I know this does not really help you, but like I said, I doubt it's driver issues, try looking deeper into your network settings.

Try resetting your routers configurations, sometimes that might help. I recently had that issue at work and the problem was solved. And this was based on over 100+ pc's on network.

What is the make and model of you modem? Who is your ISP? What router are you using and how many computers on the network? Make and model of router. Was there any software that came with this modem to install? If you could fill in your system specs with as much detail as possible, this will help us here better ascertain the issue and try to help you solve it. Try looking for a reset button on the modem and push it in and hold it for 10 seconds then release it. I'm guessing it's software/firmware update for that modem being that it's intermittent with Windows 7. Again just a best guess. Look for the modems website and see if there is any software/firmware updates to install.