My overall rating is 3 out of 5 because of ambivalence.
I had trouble compiling it due to some vague function calls, but eventually found a SourceForge page at taskscheduler.sourceforge.net that had a compiled version to download via ActiveState's PPM. The documentation did not mention this (it has a blank SEE ALSO section).
The Source Forge site refers to the Windows documentation, but that leaves something to be desired as well.
It follows the Windows interface style too closely. You use New() instead of new(), and have to manually call the End() destructor. There's no option to import constants, so you have to use Win32::TaskScheduler::CONSTANT or $obj->CONSTANT. I would rather the interface followed traditional Perl style and calling conventions.
However, I figured out how to get it to do what I needed within a few minutes. And it seems to work relatively well.