No Internet with LAN Connection

No Internet with LAN Connection

I have a client's computer that is connected via CAT5 to our network. It is receiving data back and forth (tested with ping), but there is no internet. I was able to pull up a connection to our local server. It is setup for a modem connection tethered to a cell phone. I have checked the TCP/IP settings and its setup for DHCP (like it should be), I've tried resetting the Internet Options, done a WINSOCK fix and nothing seems to be working.