Because the PPT production process, the operation of a lot of cumbersome, often for a to achieve the effect to test many times. There are too many steps to make it difficult to undo, and to start adjusting again. Then we need to increase the number of undo in the PPT to prevent this trouble from happening.
1. Switch to the File tab and click Options in the Drop-down panel.
2, in the Pop-up PowerPoint Options dialog box, switch to the Advanced tab, in the "Edit Options" column will be the maximum number of canceled operands to "50", of course, this value can be set according to their own needs, the upper limit is "150". When you have finished setting, click OK. Then you can undo the 50 steps.