Theme stylesheets not loaded
I recommend you use Aquia Dev Desktop, easier to use than Xamp, one click install.

https://dev.acquia.com/sites/default/files/downloads/dev-desktop/AcquiaDevDesktop-2-2016-09-05.exe

Just use that, and it will all work 100% the first time.

Something else you might need to do with Xamp is adjust timeouts ect...with Aquia dev desktop the settings are usually already adapted to Drupal requirements.