I want to create software that converts all installed applications in a machine into pdf format using java. I am not able to start with it. I have read all the documentation but not able to set up the things from basic.
This page shows high level supported file formats.
Here is a more detailed listing.
converts all installed applications in a machine into pdf
It sounds like you want to use our Windows Virtual Printer. First, you would install it using one of these installers (bitness has to match the OS).
https://pdftron.s3.amazonaws.com/downloads/pdfnetDrivers.zip
Then you need to make sure that there is a registered “print” or “printto” verb for each file extension you want. Each application may or may not have setup that up for you when it was installed. Right clicking the file type and checking the Windows Explorer Context Menu for a “Print” action is a good indication.
Note the print and printto verbs need to be registered with the user credentials your process is actually using, which may or may not be your user account.
If you need to manually set the registry, for apps that did not do it for you, but where the app supports printing from the command line, see this post.