You run an ipconfig and find that your IP address is 169.254.x.x with no default gateway and no access to the internet. This means that your computer was trying to find a DHCP server, but couldn't, so it gave itself an IP.
To Resolve: Edit
1. You need to check the cabling to the workstation. Reseat the ethernet cable on both ends. Verify that the port it's plugged in to is lit up on the switch.
2. Run - ncpa.cpl. What does it say as the status? Connected? Network Cable Unplugged? If the latter, resolve that first. If the computer is on DHCP, try assigning it a static IP and switch back to DHCP. Also try disabling IPv6 just for troubleshooting, you can re-enable later.
3. You need power cycle the modem, switch, and router. Get logged in to another computer on the network and find out the default gateway by running an ipconfig /all.
4. Log in to the default gateway's web gui, and see if it can see the computer with the 169.254 address at all. Look by the name of the computer (the NetBios name - found by using the keyboard shortcut Win + Pause/ Break).
5. If the router can see the computer, go to it and try this:
a. Run - cmd - netsh int ip reset reset.log ( to reset TCP/IP type)
b. Run - cmd - netsh winsock reset catalog (to reset WINSOCK type)
c. Reboot the computer.