Hopefully someone has run into this one before. I have a VB.NET process that sometimes requires an existing PDF to be deleted. Several files may be open at one time. For example, say I have File1.pdf, File2.pdf, and File3.pdf all open. During execution of my application, I get to a point where File3.pdf needs to be deleted. If I try to do this while it's open, it obviously will error. My question: How do I check to see if File3.pdf is open and, if it is, how to I close it?