What version of the Toolbox are you using? Windows 8 is supported by Toolbox versions 3.1.0 or greater.
In what way does it not work? The scheduled run of the Optimizer does not occur? You can't create a scheduled entry?
To add more detail - the SSD toolbox acts as if the task has been scheduled, but the it never runs because the task doesn't get added to Windows 8's task scheduler.