License

I have one license that I use on multiple computers.  When I tried to use the Microstation in my desktop switching from the lop top.  I got a message stating I can not access it because I only have one license.  It is my understanding that I can use one license on multiple computers so long as one user is using it at a time. 

How do I resolve this problem?  I know for a fact that there is no one using the license at this time.

Thanks.