Hi ROG O, sorry to hear you're having issues with PreSonus Studio One, we haven't done a lot of testing with this program so we're not to sure what could be happening here.
Are you able to get Serato Sample running correctly on one of our supported hosts (Ableton Live, FL Studio, Maschine, Logic Pro)?
Serato Sample should be installed using the installer wizard and is usually installed to C:\Program Files\VstPlugins - most other installers and plugins install here too. Have you made a custom location for VST plugins?
Serato Sample works fine in my Fl Studio and Maschine software. I thought it would of been good to try out your product on a new DAW. Presonus is my vocal Session DAW but I wanted it to have while just playing with ideas and cutting samples. Hopefully this can be resolved.