.net powerpoint application cant save

I wasn't sure how to formulate my title so sorry if it wasn't clear enough :)

The purpose of my application (price offers) is quite simple:

You write all client coordinates in a textbox
The mail address will automaticly be retrieved from it
All coordinates will be pasted in all the selected powerpoint templates (in the background)
These will be saved in a pdf format (using ApplicationPresentation.SaveAs(...SaveAsPdf))
Where after they will be send through the .net mailing system.

Now Since the windows update the saving doesn't seem to be working anymore. I get an unknown com error (Error -2147467259). After some research I came across someone that had UAC issues.

So I did some tryouts and indeed when I save my powerpoints to C:/ it works... The moment I try to get them on another drive it blocks and gives me an error.

Is there some configuration I need to do to a drive, to get it working? My application worked though before the windows update. So there has been an override somehwere :(

Solution

Thanks to Fabio comment I managed to find a way to my problem so his comment was certainly usefull. As it seemed my problem was a renamed folder (just a capitalized letter) I didn't checked.