To pin a file to the Recent Presentations menu list in Microsoft PowerPoint, you can follow these steps:

1. Launch Microsoft PowerPoint on your computer.
2. Open the PowerPoint file that you want to pin to the Recent Presentations list or create a new presentation if needed.
3. Once the file is open, go to the “File” tab located in the top-left corner of the PowerPoint window.
4. In the File menu, you will see a list of recent presentations under the “Recent” section. Locate the file you want to pin to the list.
5. Hover your mouse cursor over the file you wish to pin. A pin icon (a small gray pin) should appear on the right side of the file’s thumbnail.
6. Click on the pin icon next to the file you want to pin. The pin will turn blue, indicating that the file has been pinned.
7. The pinned file will now appear at the top of the Recent Presentations list, making it easily accessible for future use.

By pinning a file, it will remain in the Recent Presentations list even if you open other files, ensuring quick access to your important or frequently used presentations.