Windows XP Netbook Won't Connect To Wireless Network

I have a older ASUS Netbook
Details:
Windows XP Home SP2
Intel 1.66Ghz 982 MHz
1GB Ram
Atheros AR9285 Wireless Network Adaptor

I was having a ton of problems with it so i decided the best medicine is a Format/Reload, I have a XP installation disk as well as the driver disk that came with the PC. Everything installed fine, when I'm at home it works flawlessly, however when I take it to work I can not connect to the Wireless network there... Whenever I try I get this error:



I took the Netbook back home and uninstalled the Wireless Network Driver then re-installed it hoping it would fix it but alas it still gives me this error. I am stumped because my mobile phone and other customers computers can connect to this wireless network with no problems so i know it's my Netbook and not the router... (Plus it connected before the Format/Reload)