Do you know what the current IP address is?
You can try this, but if this is a work computer, then have your IT staff fix it for you.
1. go to control panel
2. Double click on network connections.
3. right click on local area connection and select properties.
4. Select Internet protocol (TCP/IP) and click the properties button below
5. Select obtain IP address automatically
6. Select Obtain DNS server automatically
7. Click OK on everything until exited out of network connections
Now, reboot and see what happens.