Hello, I am currently very wound up and confused because i cannot connect my second computer to the internet. Firstly ill give you some details on my situation and if you could offer any advice or help i would really appropriate it.
I connect via power-line adapters as my WiFi naffed out one day randomly. My main Pc is windows 8 and my secondary is windows 7, I can connect one or the other at a time but the other is left with the little yellow danger sign over the network icon. As for my power-line adapters, i cant connect anything but one thing at a time to them, Even though they have WiFi i cannot connect even my phone to them. They are model dLAN 200 AV Wireless N WP if that helps.
If anyone has an idea to what i can do id be very grateful!
By the way you explain your question, it seems that your network has a set amount of devices which can connect at any given time and probably this number is = to 1. Thus, when you connect your computer to the internet, none of the rest of your devices can connect and show the exclamation mark-icon in the taskbar.
Try having a look at this thread and see whether it could help you address your issue: