I have experienced a few times that when I attempting to load a sketch, and while browsing for it in Win Explorer the PC lock when trying to delete another file in that situation. I know that it may not be the right way/time to do more than to fetch the file and go?!
I am not sure if the issue is known to anyone and could be looked at.
Not sure what you mean. So ... you got a sketch opened. And then you're browsing for a file. And then you try to delete a file that is different from the one that you opened.... and the windows explorer locks up?
Could be a windows operating system issue. Could see what happens if you (temporarily) use a different computer running the same Arduino sketch software. If no issues with the second system, then the issue will probably lie with something corrupted with your operating system.