The path needs to be:
C:\Program Files\darktable\bin
either cd C:\Program Files\darktable\bin from cmd and then darktable-cltest
OR try this:
C:\Program Files\darktable\bin\darktable-cltest
For any other request, you need to do it from that same path. In example:
C:\Program Files\darktable\bin\darktable.exe -d all