Changing the IP settings from the Windows GUI is a no-brainer! I have never been a fan of using the GUI for system configuration. I change the network settings of the ethernet and wifi interfaces from the command line!
If you need to administer your home network remotely from office, you will either need to know the public IP address assigned by your ISP or use a service called dynamic DNS, that will map a DNS hostname to your IP address. Dynamic DNS is required as the public IP address assigned by your ISP is never fixed for consumer broadband connections.