Ok Guys if you are using your work laptop which works fine at Work and you have no problem connecting to your home Internet with other devices, then it's very likely your work uses Proxy Server. There is two ways about this, the easiest solution is to Run CMD on Windows and type etsh int ip reset resetlog.txt, what this will do is clear your proxy settings automatically. Beware if you are using your work laptop it will not connect to your work internet no more.
The second solutions is what I do, right click the little Icon with the screen on your task bar.. You will see two options one for Wireless and the other for Ethernet. Right click which ever one you would like to use, Click properties and on the general tab scroll down to the End. You should see "Internet Protocol (TCP/IP)" double click this and you will see a new window open. On the General tab you should see Two options, if the option is "Use the following IP address" then there is your problem. MAKE NOTES OF THE INFORMATION(IP address, DNS, Subnet Mask, etc) IF YOU WANT TO RECONNECT AT WORK. Now once you have made notes (write it down on paper) and click the other option which says "Obtain IP address automatically" Careful once you click this your previous info will be lost. Click OK and Disabled Your Internet connection and reconnect.
That Should do it..
Once at work follow these steps and type the information back as it was and again reset your internet connection via your Laptop.
Hope this Helps and Im using Windows XP. For Vista it might be slightly different but you should figure it out.