Thanks everyone for your help and explanation.
What is CLI? If it is an application, where can I find it?
I have a file with the following format jbdocpdf.tar.gz. After running Winace it creates a file jbdocpdf.tar; continue doing so, it creates many other small *.pdf files. Unfortunately, all the files has 0 bytes even though the original files is 25MB. I also try Winrar in vain, it displays "no archive founnd in selected files". What I am missing here? Any kind of help is greatly appreciated.