Maybe find some free online storage, and upload them for later.

I'd be curious to know the path to the files and how big are most of these files ? Perhaps they are clipart from one of the graphic programs or word.

You will have to be extremely careful in what you delete ie bulk deletions, as some may very well be used in other applications ie MS Word etc

39,000 sounds like far too many to be part of any software program. What do these files look like when you view a few of them? How much space do they take up on your HD? Where are they (what is the file path)?

If the answers to these questions don't produce explanations, then one possibility is that your security has been compromised and your computer is being used as a file storage site as part of a botnet.

One site I looked at listed two kinds of files with that extension:
PNP PEERNET Publisher (PEERNET Inc.)
PNP Pegasus Mail POP3 Server Side Filter Rules (David Harris)

Wring extension. There were three:
PNG Portable (Public) Network Graphic
PNG Paint Shop Pro Browser Catalog (Corel Corporation)
PNG Fireworks Image File (Macromedia)

Where they are located may tell you lots. When you do the search for *.png, you have the details view option to see where they are - what directory/folder they are in. You can delete the whole folder(s), which is faster and less draining on system resources than mass deleting lots of files.

As already mentioned, some might be associated with other programs so be careful. Because you don't recognize the images does not mean you don't want to keep them. I find 453 png files doing a search. While most are associated with Jasc (including plugins) or other image editing and video programs, a few are part of my Service Pack files, some are from my DVD burning software, and many are in the System32 directory (associated with DirectX, which you want on your computer). I wouldn't touch any of them. Because you don't want Jasc or Corel on your computer, only remove the ones associated with the programs you don't want or already deleted.

I doubt they mysteriously appeared as in you or someone else downloaded png files by accident. You did it when installing programs and downloading programs and other necessities.

Also, it might ease your mind a little to know png files are not normally very big. PNG format was designed to be able to display millions of colors (almost limitless) while being better compressed than JPG format, which is already considered to be well compressed with no loss of color. I realize 39,000 is a lot, but most of mine are only 1kb. If we assumed all of yours are only 1kb, that only amounts to just about 40mg, which is very little compared to 120gig hard drive. Adding the unlikelihood they are all just 1kb, I still doubt they collectively amount to 100mg, which is still very little consumed space.

I just did a Search on my computer and I found a few hundred of them.. Most are for Direct X and WinAmp skins... I wouldn't delete them unless you've already un-installed the program that they work with...

Rita

Okay, case is mostly solved. I found that 39,000 plus got to about 10,000 after removing Open Office - which I downloaded but didn't use. A few hundred more were zapped upon removing a couple of other programs that I also didn't use. The count now is around 9,700 and most of them are related/connected with the Opera browser. Aside from the Windows, system, and other essential programs, the remainder is spread among the rest of the software that I will keep for now. As some of you stated, most were in the 1kb - 5kb range and did not amount to a problem of storage. Perhaps I'll wean myself away from Opera, relying almost solely on Mozilla. Thank you for your input, suggestions and cautions.