I use a program called PDFStapler for this, which is completely free and can be downloaded HERE. You will download a compressed file that needs to be extracted and you can start the program. The program does not require a separate installation. I illustrate the program in the picture below. Do not look for the Open File button. The PDF files to be concatenated must be included in the file window as usual. The files will be concatenated in the order in which they appear in the window. Use the red x to delete a PDF file from the list that you don't need. [img alt_text = 'PDF concatenation' description = ''] https:///wp-content/uploads/2016/11/pdf-osszefuzes.png [/ img] In the ouput file field, enter the name of the concatenated file, which is created. Then click STAPLE MUSHROOMS and you're done.