How to avoide proxy in the computer and connect another computer to the internet ?

I’ve a computer at work it seems protacted by proxy , the issue i cannot loging or connect any more computer to this network.
i want to be able to connect the other computer to the network.

i think i have a tip it could help

the IT guy did that :
loging to tools\internet option \ connection \ LAN setting and wrote http://sanicvm01.petrobras.biz/inet-lba.pac