assuming you have connected direct to pc then i guess you need to set up pppoe at pc
guide is here
http://www.draytek.co.uk/support/kb_vigor100_setup.html
How ever i will say to try with firmware utility tool to updade again
I also find this post if will help and you have the time to do it
Sounds like your modem or Internet connection from you Internet provider to your modem is malfunctioning.
Some ideas:
To prove this, disconnect the network cable from your modem, and connect using a network cable from your modem to a computer's wired LAN port. Temporarily turn off Wi-Fi in the computer, if Wi-Fi is on. Reboot your modem, then computer.
Run http://speedtest.phonepower.com/. After the test click on the Advanced tab and post.
Next click on the Graph Tab. Go down to the Left lower side where you will see the word Plot:
Look at all four plots.
Pay attention to the Download Speed and Upload speed plots. Look at the red graph lines.
If you have a very few narrow red spikes going up to about 3/4 of the way to the top of the graph, they are not good, but probably won't cause a problem.
If you have red spikes that are wide and go to the top of the graph and farther if there was room, there is your problem.
Either the modem or Internet provider's signal isn't good.
If you see this especially on the Upload side, it most likely the spikes being generated from the modem.
