Fix second monitor configuration on windows XP as desktop extension one above the other

I am running windows XP on a dell laptop. At work I connect a second monitor and I use it as an extension of my windows desktop. And because my monitors are physically one above the other I rearrange the monitors in the system to reflect this. (This way I drag files from the monitor on the bottom to the monitor on top by moving the files up.)
The problem is that every time I turn on my laptop at home (where I don’t have two monitors) and then come back to the office, the configuration of the second monitor is lost and I have to rearrange them again one on top of the other.
 Is there a way to fix the monitor configuration when I have 2 monitors to be one on top of the other? And still be able to use my laptop at home with just one monitor and not loose the configuration for the second monitor?