PowerPoint Presentation recovered but not opening

Hello, I came here out of desperation. When I formatted the pc to install a new SSD two vital files for my work didn't copy into my hard disk. I found them via deep search. One was in excellent conditions the other one was in poor condition but since they were at least similar it's ok.

I tried to open them and power point failed, it then said I could recover them, but it said it didn't have access.

Is it because they were saved on my old desktop? and if so is there a way to open them anyway?

Thanks in advance to whoever will be so kind to answer.

Ps.

I run the latest version of powerpoint on windows 8.1, the file is a .pptx

Recuva will recover whatever is in the clusters it considers are associated with that file. The contents are not necessarily valid files, the clusters could have been overwritten or be incomplete (deep scan will not recover fragmented files). I don't have any knowledge of PP's recovery, but I don't think it's likely that it will somehow retrieve the data.