Microsoft Windows 7, 8 or higher + Internet Explorer 10 or higher SketchUp 2014 is not fully supported under windows XP, see: help.sketchup.com/en/article/36208
A fully working internet connection is needed once during license activation.
First download and install Skalp version for your SketchUp version. (Installation instructions, see: manual)
From inside Skalp request a FREE 14 day TRIAL. Your ‘License Activation Code’ will be sent to your email address.
Activate Skalp using the received ‘License Activation Code’. (Menu bar > Plugins > Skalp > Info dialog > activate)
Future product updates can be installed automatically from inside SketchUp/Skalp.