my library browser won't show up

[pintodesign]

just started using X6. No matter what I do, my library browser won't show up - I must be losing my mind.
I had updated all the library content when I did the install. Everything works fine, but I can't "find" the library browser. I once had that happen when switching from using multiple monitors back to a laptop (the library had been open on a second monitor), but I was able to find a setting where I could "dock" the library, so it showed up (that was in X5). I've been through all the defaults, preferences settings and can't find anywhere to reset that. I'm currently using two monitors, so it seem like it would show up somewhere.
What am I missing???
Thanks
Barb