To fix a corrupted PowerPoint file, you can try the following steps given below:
-Restore from the backup. You create backup to prevent the situation of data loss due to corruption or accidentally deletion. If you have backed up the PowerPoint files, you can restore them from the backup.
But if not, then
-Use Data migration. It is one of the easiest ways to recover data from a corrupt file. First you need to create a new presentation file.
Then by using the Insert menu, you can import all the slides from a corrupt file to this new file. But sometimes this could be ineffective or failed due to severe corruption. If this happens, you can try the next one
-Use TMP files. Whenever a file gets corrupted or deleted, there is a temporary aka TMP file available in the system. You need to locate it.
If the TMP file is successfully located, you can restore the corrupted PowerPoint file. This could be a difficult task for a novice or non-technical users to perform as it may require a lot of technical understanding. Do not be hopeless as one more solution is there
-Use MS Word or other programs. You can try to open our corrupt presentation file in MS Word. If the file can be opened, you can recover at least the text part of the file. Other than this, you can also try to open the file in OpenOffice Impress. Unluckily if the files are still unable to be opened, the last and effective solution could be a
-Use a Third party tool: This must be the best and effective solution for recovering corrupt PowerPoint files. A third-party tool is designed to handle any level of corruption from corrupted files PowerPoint Repair Toolbox
http://www.powerpoint.repairtoolbox.com/