Issue: My computer isn't opening PDF files in Adobe Acrobat, but I have the software installed on my device.

Your computer may not have Adobe Acrobat set as the default app to open PDF files. Follow the steps below for your computer operating system to set the default app to open PDF files.

Windows 11

To set the default PDF app on Windows 11, go to Settings > Apps > Default apps, select your desired PDF application, and then click Set default. Alternatively, right-click any PDF file, choose Open with > Choose another app, select your preferred app, and check the "Always" box. 

Method 1: Through Settings

1. Open Settings by clicking the Start button and then the gear icon.
2. Click on Apps in the left-hand menu.
3. Select Default apps.
4. Find and click on the application you want to set as the default PDF viewer (e.g., Adobe Acrobat).
5. Click the Set default button at the top of the screen. 

Method 2: Using a PDF file

1. Navigate to any PDF file in File Explorer.
2. Right-click the file and select Open with.
3. Choose Choose another app.
4. Select your preferred application from the list. If it's not visible, click "More apps" to browse.
5. Check the box next to Always use this app to open .pdf files.
6. Click OK. 

Mac OS

To set the default PDF app on a Mac, find any PDF file, right-click it, and select "Get Info." In the "Get Info" window, click the "Open with" dropdown menu to choose your preferred application, then click "Change All" to apply this setting to all PDFs. 

Step-by-step guide

1. Find any PDF file on your Mac and right-click it (or Control-click).
2. Select Get Info from the context menu.
3. In the "Get Info" window, find the "Open with:" section and click the dropdown arrow to expand it.
4. Choose the application you want to be the default from the list.
5. Click the Change All... button.
6. A confirmation dialog will appear; click Continue to set the new default application.