Sounds like you need to do an IPCONFIG/_renew
Go to start/run/ type in cmd and hit okay
At the prompt, type in ipconfig/_renew
Hit the enter key.
Your computer should find an ip address.
That underline is actually a SPACE after the forward slash before the word RENEW
The other thing you could do is type: ipconfig/_release
Then after that type IPCONFIG/renew
This should release any old ip address the modem is not finding and then it will renew the IP address from the modem.
Give it a try.
micro...