See what you can do to fix the problem quickly. Adobe Acrobat Reader could not open PDF Earlier, Acrobat products performed no checks on the extraneous bytes present before the %PDF-header.

Once you've decided on a native or alternative PDF reader to open your file and changed your Windows settings, locate the PDF file in File Explorer. Either double-click the file or right-click the ...

The PDF file type is most commonly associated with Adobe Acrobat Reader. To be able to open these files you need to make sure that this program is properly associated with this file type.

The files will begin to upload to PDF Joiner (this could take a few minutes, depending on how many and how large your files are). Click Join Files in the bottom right-hand corner of the screen.

If you want to merge multiple PDF files into one, there are multiple ways to do that on Windows 11. You can use a free desktop app, a website, or run a command from Command Prompt to combine the ...

However, this default setting makes it difficult to open multiple PDF files in separate windows. You can change this setting within Acrobat and force PDF documents to open in new windows.

The big difference is that if you want to use the keyboard, there is CMD+o to open files in Mac OS, whereas it's Enter in Windows.