Icons turning into unknown program icons
 

It was just yesterday when I noticed several file icons in my laptop had turned into an icon for unknown programs. The files affected are mp3s, any Internet documents (not the Internet browser program), Show Desktop icon, Microsoft Outlook, and several games.

I thought maybe it was a pesky virus(es) and/or malware(s), so I did a thorough scan. The result was negative. Curious by this, I ended up trying to run the files and found out the files were working fine; only the icons that changed.

I thought maybe the computer crashed a bit and restarted it. The icons, as expected, returned to normal EXCEPT the Firefox documents and the Show Desktop icon. But after some time, the Show Desktop returned to normal.

Just a few hours ago, I switched on my laptop and found the condition persisted.

What is the problem here?

Try this first:
Rebuild icon cache to fix incorrectly displayed icons | Troubleshoot | Smallvoid.com

Yes, that solves the problem.

Thanks. I'm closing this.