I have discovered some old .pxn files on my PC.  I think that they may be graphic files associated with Kodak software.  Does ANYONE know how to open these?They were indeed related to a Kodak app KNOWN as PictureWorks...
Whether you can FIND that now or not i don't know.
You may want to try their EasyShare software which i believe is still Free at their site.

Found a Free version here...
Thanks PATIO,

I had a copy of EasyShare which I have already loaded.  This didn't help.  I have installed some viewers from the web but most of these didn't open the files.  There was one, Universal VIEWER, that let me open a file as a binary dump.  This displayed a lot of seemingly random text with chunks of old emails dotted about.  The .pxn files I was trying load came from a file recovery run on my PC.  Can anyone offer an explanation about this? I would try this...pick one file and move it to a folder...
Then use a graphics app of your choice to convert it into a well known format such as jpeg ...
Then see what happens.