Hi Gustav,
If you follow exactly the instuctions on the potree.org site, you should have your web pages located in the folder:
C:\XAMPP\htdocs
It should no be necessary to install the XAMPP if you have the web server already set up.
Just run the converter, and take the output (what's in C:\xampp\htdocs\potree) and place that in correct place on your web server.
Does this help?
Best regards,
Marko Myllymaa