I’m also on Win10. I just tried detaching the parts as @microMerlin suggested, and then did an alt-tab but that doesn’t show the detached panel just the main Fritzing window (unfortunately snip-andsketch won’t capture the alt-tab window, but only the main Fritzing window appears not the detached parts window.)
windows-key tab gets a similar screen that snip and sketch will capture
but only the main Fritzing window shows not the parts detached window. I haven’t ever managed to move the detached window off the desktop so I have never run in to this before and don’t know how to recover from it.
Peter