Were you able to confirm the service is pointing at
        stunnel.conf and not stunnel.cfg maybe?
        
        > Date: Thu, 21 Aug 2014 16:43:16 -0700
          > From: 
541401@gmail.com
          > To: 
stunnel-users@stunnel.org
          > Subject: [stunnel-users] Stunnel Windows Server 2008 R2
          > 
          > I have installed stunnel 5.03 on Windows Server 2008 R2
          X64. When I 
          > run it as an application it works perfectly. When I
          install and run the 
          > service, it starts but the start notice window, title
          bar, says Stunnel 
          > 5.03 win32 (not configured). It appears that the stunnel
          service is not 
          > reading the stunnel.conf.
          > 
          > If anyone has any suggestions how I can successfully run
          stunnel as a 
          > service, I would be very appreciative.
          > 
          > Thank you!
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