Where to install the Hardware folder

On my machine, a Dell Laptop with Windows 7, the Arduino package installed itself in c:\Program Files (x86) and the Sketchbook was created in c:\Users\grayl\My Documents\Arduino, within which is a folder named Libraries. In trying to get my new LCD4x20I2C display to function, initially I copied the zip file to the Libraries folder, but ran into a problem when I tried to use two different libraries contained in folder containers of the same name. Then elsewhere it stated that I needed to have a Hardware folder but it was unclear whether the Hardware folder was in Arduino folder or in the Libraries folder. Can someone clarify that for me? If you have any pointers as to where to install libraries versus sketches, I will appreciate. A step-by-step would be appreciated. Here is what I am trying to install:
http://www.dfrobot.com/wiki/index.php?title=I2C_TWI_LCD2004_(SKU:DFR0154)

The hardware folder is for hardware definitions for things like different processor boards with different pinouts.

If you have two libraries with the same name it is possible you have a duplicate library possibly with different versions.

If this is not the case then put the library somewhere else, unzip it, rename the folder to a non conflicting name without hypens (-) and preferably no underscores or spaces, rezip with a new zipfile name and then try importing it.

On my machine:

C:->users->grayl->MyDocuments->Arduino->Libraries->LCD_I2C or

C:->users->grayl->MyDocuments->Arduino->Hardware->Libraries->LCD_I2C ??

In both cases folder LCD_I2C contains these files:

examples
diff.txt
keywords.txt
LiquidCrystal_I2C.cpp
LiquidCrystal_I2C.h
LiquidCrystal_I2C.o

They sound like the same library. It also seems that undescores are OK. (I think hyphens are definitely an issue).

Have you check to see if they are not both the same library?

Please share example code & associated library in zip file. SO we can update share it back.