In their infinite wisdom, Google decided that Chrome should provide its own metro-style user interface when running under Windows 8. So Google created Windows 8 mode, providing the Shelf for application icons (similar to the Windows task bar), which replaces the desktop when running and prevents the user from directly accessing all of their other open windows (really smart move). Last time I checked, most Windows users would like to have access to their application windows when using their system; what a novel concept!
So the latest versions of Chrome running under Windows 8 have both a Windows 8 mode and a Desktop mode. Chrome may launch in Windows 8 mode by default on Windows 8 systems. Do the following to change it to Desktop mode so all the other Windows windows can be easily accessed.
Click the Chrome Menu button at the top right corner to open the dropdown menu panel. Click the menu item "Relaunch Chrome on the desktop". Chrome will briefly close then reopen as a normal Windows window and allow access to all your other open application windows. Chrome does store your preferences so that all future sessions will open in Desktop mode until it is changed.
To return to the Windows 8 mode, open the Chrome Menu and click on "Relaunch Chrome in Windows 8 mode".