There are a couple of possibilities: by freeze does Windows say that Fritzing is not responding and offer to close it, or is it just not doing anything? If it isn’t apparantly doing anything, just wait, it goes to github to do an update of the parts library without any progress bar or other indication and sometimes that takes 5 minutes or more before completing. If the not responding message comes up you may have a corrupted data base file in which case deleting or renaming these two directories may clear the problem. There was one report lately from a Win10 user that Fritzing froze on file open that I don’t think we every found a cure for, hopefully this isn’t your case and the fix below helps.
There are two user directories (with your parts and the parts database) which don’t get touched during an install (to not affect your sketchs during upgrades). On Windows they are in
c:\users\username\AppData\Fritzing\roaming\Fritzing (which is a hidden directory so you need to enable hidden directories in explorer) and
c:\Users\username\My Documents\Fritzing (where username is your windows id)
If you don’t have any parts or sketches you want to keep you can just delete those two directories and Fritzing will receate them, or you can move them aside by renaming them if you wan to keep something in them.