I think your router firewall settings are the problem with the router. When you just hooked up the old PC(when I had you turn off the windows firewall) was it thru the router or direct to the modem?
I could not get an online manual for your router but want you to reset it after you change a setting. Charter pipeline connects thru a proxy server according to the web site, the following link is there instructions for setting this.
Proxy setting
After setting this I want you to reset your router the following are instructions from netgear.
To reset your netgear router try the following.
Press the reset button on the back until the test light blinks. (To avoid accidental resets, the small button is recessed. Use a pen or paperclip to access it.)
Wait for the router to reboot, then try logging in with the default password.
If the router was not cleared, try these additional steps AFTER the router has finished rebooting.
Unplug the router's power.
Press and hold the reset button. While the button is held down, reconnect router's power.
Continue to hold the reset button for 20 seconds after reconnecting the power.
Wait for the router to reboot.
Log in with the default password.
This is what they list for passwords.
The router username is always admin
The default password is password or (for some older routers) 1234
The address the netgear site shows to get into your router setup is 192.168.0.1 but if you have a software method use it instead.
With a new PC to play with you might not feel like working out this problem right now. If that is the case post back and you can send me a PM sometime and we can arrange a better time to solve this if you want. If you want to get it fixed so your girl can get online too, the problems are definitly repairable without to much trouble.