Place PDFTK.exe in to the following location - C:\Windows\System32
(1)Load all PDF's into one Folder
Right-click on that folder, and select Command Prompt Here
(3)Once the Command prompt has loaded type the following
pdftk *.pdf cat output (NAME OF PDF).pdf -This command will create the combined PDF in the order that they files are in with in your folder
pdftk 3.pdf 2.pdf 1.pdf cat output (NAME OF PDF).pdf - This command will create the Combined PDF in the order that you have defined.
(4) Combined PDF will then be created and be within the folder with the remaining PDF's
for HELP in the Command Propmt type - pdftk --help