If you want to extract and save a single slide from an existing PowerPoint presentation, the best thing for you to do is to copy the slide and paste it into a blank PowerPoint presentation.
Select the slide from the “Slide Thumbnail View” on the left part of your PowerPoint window. Then, “right-click” on the slide. From the options that are displayed in the menu, click on “Copy“.
Click on the “File” tab on the top. You will be taken to the backend view. From the backend view, simply click on the “New” option on the left, and then select the “Blank Presentation” option.
Click on the first slide in the new presentation, and paste the slide that you have copied. You can “right-click” on the first slide, and from the options that appear, click on “Paste“.
Click on the small “clipboard” icon underneath the slide that you just pasted in the new presentation. Choose the “Keep Source Formatting” option from the dropdown.
Delete any additional slides that may be present in the new presentation. To delete the slides, select it by clicking on it. Then, right-click and choose the “Delete Slides” option.