External drives and Vista

Paul, I’m a new to this forum site.  For some reason I think this is a windows/vista problem.  I did a recent recommended by windows update to my laptop, which changed several things on my computer, one of which was sidenotes!  Yesterday I did a backup using my WD Passport Essential, and my computer wouldn’t recoginize it.  This was not the first time I backed up to the WD, but was the first time since I updated Vista.  Maybe you’ve done the same thing and just haven’t made the connection.  I keep a log of everything I install on this laptop in case it crashes and I can’t get to the internal information.   sorry not much help.