There can be many reasons for it, however it is hard to give you a solid answer due to lack of information.
So as a long Shot:light:
The first step is to ascertain that you have a functional Wireless connection.
Unfortunately seeing a Good signal or seeing the name of your device in the Wireless Properties, or the word Connected, does not mean that you have a working connection.
Working connection would mean that a least you can log to the Router's Menus system and browse them, or you can connect and exchange info with another computer on the Network, or you can browse the Internet. If none of the three is working it most likely you do not have a Functional Wireless Connection.
Wireless - Basic Configuration:
http://www.ezlan.net/Wireless_Config.html
Wireless - Security -
http://www.ezlan.net/Wireless_Security.html
Might be that your Wireless is configured with parameters that fit the office Network but not your home Wireless.
Configuring a Laptop (or any computer) to connect to more than one Network.
http://www.ezlan.net/faq#fewtcp-ip
:sun: