To download Adobe Acrobat Reader, the free PDF viewing software, follow these steps:

1. Visit Adobe's Official Website: Open your web browser and go to the official Adobe website. The URL is "https://get.adobe.com/reader/."

2. Download Page: You will be directed to the Adobe Acrobat Reader download page.

3. Optional: Uncheck Optional Offers: Adobe often bundles other software with its downloads. On the download page, you may see checkboxes for optional offers or products. Make sure to uncheck these options.

4. Select Your Operating System: Adobe Acrobat Reader is available for Windows, macOS, Android, and iOS. The website should automatically detect your operating system and display the correct version for you. If it doesn't, use the drop-down menu to select your operating system.

5. Click "Download Now": Once you've selected your operating system, click the "Download Now" button. This will start the download process.

6. Download Progress: The download progress will be displayed in your browser. Depending on your internet connection speed, it may take a few moments to complete.

7. Run the Installer: When the download is finished, locate the installer file (usually in your computer's Downloads folder) and double-click it to run it.

8. Follow Installation Instructions: The installer will guide you through the installation process. Follow the on-screen instructions to complete the installation.

9. Now try to open the PDF pattern file. It should open with Adobe Acrobat. However you might need to right click on the file to choose "Open with" and select Adobe Acrobat.