Installing fonts in Microsoft Windows is quick and simple, but if you want to perform a PowerPoint presentation it is recommended that you make sure the font is present in the computer where you plan to play the Slideshow. To be safe, you can prevent using any custom font and try to use the safe fonts in powerpoint instead. This will avoid some future problems and disasters when you move the file to another computer and the fonts are replaced with another one that is not the one you used to design the Slides.
However, if you need to use custom fonts then a good approach would be to make sure the fonts are installed in in the computer where you plan to run the PPT presentation. Many font packages you download from the Internet may be contained in compressed .zip files to reduce file size and make downloading faster. If you have downloaded a font that is saved in .zip format, you can “unzip” it by double-clicking the icon for the font and following the instructions on the screen
You can learn more in how to add new fonts to the computer. This article from the official Microsoft’s website explains how to find new fonts and install them in your computer.