Set another IP address when there is no DHCP on Vista

Go to Control Panel> Network Center and sharing. Click on the sidebar: Manage network connections. Appears the list of network connections on the computer.
Make a right click> properties on the connection you want. Choose "Internet Protocol (TCP / IP)" in the "This connection uses the following elements".

Click on "Properties". In the General tab, while leaving automatic, it helps in normal to go through the normal DHCP services. In the "Alternate Configuration", check "User configured, and complete all required fields.

This alternative configuration will be used only if the first does not give good results. On a LAN, it allows for example, if exactly the same configuration in the "Alternate Configuration" than can be achieved automatically under normal circumstances, to continue to operate failure DHCP servers in keeping the same parameters, and therefore without problems to the network (typically two users who force their ip to the same value).