I just wanted to let people know I found a bug in the stored procedure portion of this that may result in the @@SERVERNAME system variable being set to NULL after a restart on the machine this routine is executed on. Details and a fix are at http://shaunjstuart.com/archive/2011/01/drive-space-monitoring-gets-an-update-bug-fix. Not sure if this is due to a bug in the sp_dropserver system stored procedure or if it is by design.