Horray for recognizing the connection.
I would suggest accessing your router settings by typing in the IP address (should be 192.168.0.1 on a DLink router, but I'm not sure) into the address bar of your internet browser on an internet-connected computer on your network. Enter in the user name (usually "admin") and password (usually left blank) or as found in the instructions that came with your router into the login window that comes up. Once logged on, run the setup wizard (more information about this in the instructions or on the internet). Your router will have to restart.
If this doesnt work, disconnect all computers from your router except for the work laptop. Restart it and try to connect. Something with your router settings may only be allowing __# of computers on your network.
If you can't login to the router settings (explained above), disconnect all but 1 computer from the network (one that connects to the internet
), resart, and try again.
If THAT doesnt work, you may have to resort to pushing the reset button on your router (hold it in) and disconnecting all of your computers from the network (except for 1 again), resarting that computer, and trying again.
Just throwing out ideas that have worked in the past.
Lets see, what else...
To join a Workgroup, right click on "My Computer" and select Properties. A window should come up entitled "System Properties". Go to the Network Identification tab and click the Properties button. From here, you can enter in your desired computer name and the workgroup name. You will need to restart your computer after making these changes.
Any more tips I can give I'll be happy to provide. Good luck
EDIT: I forgot to mention.... The laptop is probably set up with the company's Domain instead of a Workgroup. You might be able to save the domain name and instead enter and use a workgroup, but write down the domain in case you ever have to return the computer back to the company.