I used to be able to simply move the x-plane window enabling me to enter my desktop environment and open other applications, such as Google Earth, web-browser etc.  Now that doesn't seem possible.  I also used to be able to effect this by disabling 'full screen' under settings/rendering, but this doesn't seem to work now either.  What I've been doing lately is opening 'About X-plane', clicking the link on the promo video, and pausing it - then entering my desktop, but this is onerous when trying to switch back and forth between x-plane and a complex tutorial, for example.  
Thanks!