First, check your corporate policy. You're probably not allowed to plug your home computers into the corporate network. I'd go slightly nuts if I found any of my users doing that. You'll be lucky if your work doesn't do the same. You should know better.
Without a WINS server on the network: You can't remove it manually. The NetBIOS Master Browser has it cached now and will retain that as long as it's caching policy is set for (default is 6 days). You'd have to shutdown all possible NetBIOS Masters Browsers at the same time to clear the collective cache (when the current MB becomes unavailable an election occur and the winner will become the new MB using it's local cache as the MB cache).
With a WINS server: The WINS server has the entry now. If you have access to that server you can delete the entry there. Otherwise it should expire after 6 days (be default); and will be tombstoned (actually deleted) after another 6 days (again by default).