Default botton of Lightroom 4.3 - where?

Sirs,
I just start to learn Lr and play around too much, now I cannot go back to the original interface. Anyone can help? Thank you so much.

Get a Lightroom book. I find mine indispensable. I have Scott Kelby's book for LR3, but for the most part it still applies. I am using LR4.4 and the book still helps when I can't figure something out.

Version 4 of Mr. Kelby's book at Amazon.com:
http://www.amazon.com …rds=Lightroom+s​cott+kelby

You'll need to learn to overlook some of his silly humor. The information in the book is solid.

Good question. I haven't come across any "reset ui" option yet. What part of the original interface are you looking to get back, and what don't you like about the current layout you have? (I study interface design, so always like to hear about people's issues.)

1. Sorry Luckless, I might have used wrong word. I mean the first page of Lr appearing when this program is downloaded.
2. I played around too much and could not get back to this first preset.
3. If no one could not help. I would uninstall this program, and install it back again. I could not think of any way to solve my own problem. But it seems silly. I want smart people to help me. So.
Thank you so much for your comment.

Are you talking about the Library tab?

You can click on it in the upper right corner, or just hit "g" for grid or "l" for loupe. Either of those take you back to the library.

Or maybe you need to hit shift-tab. This will show the menus on the left and right.

Maybe post a screen shot as to what you are looking at and it might be easier to tell you what to do.

Definitely buy a book, Scott Kelby, Martin Evening or Victoria Brampton. They are all great options.

Check out the Lr tutorials on SLRlounge.com. I use them all of the time. I bet they have your answer there.