After updating to latest Acrobat 11, there is a new column on the left screen which has taken up all the space. This annoying feature is permanent there and reduce my precious screen size. Most important it spoilt your reading pleasure.
Thanks to Adobe forum which provide a solution.
1. Turn off Acrobat Reader
2. Then go to your Acrobat Reader installation folder (C:\Program Files (x86)\Adobe\Reader 11.0\Reader\Services)
3. Delete this 2 files: DEXEchoSign.spi and DEXShare.spi
4. After deleting the files, restarting Adobe and clicking on the Tools, and Sign buttons, they dissapeared.
5. Next time I started Adobe they were totally gone.