Step 1 click the following link to download Advanced PDF Tools
please unpack it when download is finished.
Step 2 launch the MS-DOS command prompt window. Because theis bound to be operated under the MS-DOS environment. The procedure is easy, and the following pictures will guide you.
1) click “start” and then go to “Run”
2) input cmd into the following
3) press “ok”, you will find MS-DOS command prompt window popping up
Step 3 inputto
it goes below
pdftools.exe -i C:\*.pdf -o D:\*.pdf -S openpwd=xux -S keylen=2
- the option -i is to specify a pdf filename or a directory for input,
- the option -o is to specify the pdf file name for output,
- -S openpwd=xux to set a user password as xux
- -S keylen=2 refers to 128 bit AES encryption (Acrobat 7 or higher)
when the input is done, press “enter” key, you will see
Step 4 open the file to check if opening the file an open password is needed
and you can type the open password xux to open it
So far you are successful in setting an open password.