Touchscreens have been appearing on various all-in-one desktops for some time now. The problem was that the Windows operating system and its various programs weren't really designed with more than basic touch interface functions like a mouse. This has changed with Windows 8 and the Modern UI being much more like a tablet. Lenovo has updated their 23-inch touchscreen system to try and take advantage of this while also trying to keep the costs down. Does this $900 all-in-one have enough to differentiate itself from a growing number of competitors? Find out in my review of the Lenovo IdeaCentre B540 23-inch all-in-one.