Here are some things to consider when troubleshooting a white screen issue with your PowerPoint slide show:

1. Check that you have the latest version of Microsoft PowerPoint installed on your computer
2. Ensure that your PowerPoint presentation was saved using the correct .ppt or .pptx format
3. Try closing and re-opening the presentation
4. Check that the graphics in your presentation are compatible with the version of Microsoft Office you have installed
5. Verify if any security settings are preventing the PowerPoint from running correctly
6. Reboot your computer