I ran Recuva and found 18 image files on an SD card but it won't open, preview or display the images which are in PNG format. Do I need to buy the advanced version of Recuva?
The paid-for-version is no different (as far as file recovery goes) then the free version.
How were the files deleted from the CD card?
Have a look here; http://forum.piriform.com/index.php?showtopic=41000&hl=irfanview&do=findComment&comment=249052
and here; http://forum.piriform.com/index.php?showtopic=39946&hl=irfanview