Looking for tools to recover corrupt power point file

I have a power point file that I cannot open for some reason I get the error “powerpoint cannot open the file represented by…
The selected file does not appear to be a valid Microsoft PowerPoint file. It might be another kind of Microsoft Office file or a file created by using a different product.
I am using powerpoint 2003 I created it myself and it is not encrypted and I’ve tried everything to open it.
Any suggestions?