You can use a free desktop app, a website, or run a command from Command Prompt to combine the files. Windows 11 doesn’t have a built-in option to merge PDF files.

Regdiff is a free software that lets you easily compare, merge and sort registry files. You can directly compare reg files with each other or with the local registry values on your system.

Learn how to copy files using Command Prompt (copy and xcopy). You can also use parameters to perform some specific tasks while copying.

You can combine multiple PDF files into a single, easy-to-share document using simple software on your Mac computer or Windows PC. Here's how.

Another good free-to-use option is PDFsam Basic. This program lets you combine, split, rotate, and extract both individual pages and full PDF files.