Slides on a downloaded ppt contain scrambled letters

Scrambled letters in a downloaded PowerPoint are commonly caused by font substitution or a graphics rendering issue.

Try these fixes in order:

1. Close and reopen PowerPoint after opening the file once.
2. Check whether the presentation is using fonts that are not installed on the computer. If a presentation contains fonts that are missing, PowerPoint substitutes available fonts, which can make text look wrong.
3. If possible, replace the affected fonts with common fonts such as Times New Roman or Arial.
4. If the file uses third-party fonts, install those fonts, then close and reopen PowerPoint. Third-party fonts can also fail to display correctly on other computers if they are not installed there.
5. Update Office to the latest version. In some PowerPoint text display issues, Microsoft fixed the problem in later builds.
6. If the text still appears abnormal, disable hardware graphics acceleration in PowerPoint:
   • Go to File > Options > Advanced
   • Under Display, select Disable hardware graphics acceleration
   • Also select Disable slide show hardware graphics acceleration
   • Select OK
7. If PowerPoint is also hanging or freezing, install the latest Office updates first, then continue with add-in checks or Office repair.

If the presentation looks correct on other computers but not on this one, the strongest matches are:

• missing fonts on the computer
• a hardware graphics acceleration issue in PowerPoint

• My fonts have changed
• Use decorative fonts from third-party vendors
• Problems with text, underline, and flickering screens when using Office edit languages
• Abnormal display of Microsoft Yahei font in PPT - Microsoft Q&A
• PowerPoint isn't responding, hangs or freezes