Add a second computer?

WD External Drives External Drives for Mac
1

I have been successfully backing up my computer to a WD My Book Essential from my desktop Mac for some time. I would like to begin backing up my laptop as well.  I have some questions:

  1. Is it possible to add a second computer at this point, or do I need to erase the WD drive and reconfigure it?
  2. If I it is possible to add a second computer, does it matter if the two computers run on different versions of the Mac OS?  (One runs OSX 10.5.8, the other OSX 10.6.  Neither one can be upgraded any further.)
  3. I will be getting a new desktop computer eventually.  What are the implications for adding this computer to my backup processes?

Thanks to all who reply.

2

Not a problem

you can backup multiple computers and the backup will be store separately

it does not matter if you have two different OS versions as long as they are supported

the drive works with versions from 10.4 and up