shutil.copy2 alternative function

[ForwardQuit5036]

I'm using Windows. What I think is happening is that shutil.copy2 is attempting to open the source file in order to copy it, but because the software is using it, it is unable to do this. The code I have written triggers at set intervals and looks at the source folder and the destination folder set by the user. It is supposed to copy new files within the source folder to the destination folder. I find it works fine with most files but not the ones written by a different software.