|Depends on what type of DHCP server you are referring to. If you are running a Domain controller then you configure it there.|
If you are getting your DHCP from a router then you set it in the routers configuration.
If you mean the DHCP lease on your public IP you get from your ISP then there is nothing you can do about that at it is entirely in the hands of your ISP. However, it is unlikely that an ISP will be issuing an infinite lease but it is possible.