I have for the past two years done an uninstall first and then the install of the new version. A reboot isn't necessary but after we do the install we do any Windows Updates and then reboot just to be safe. The entire process takes less than five minutes from Uninstall, Updates, Reboot, and then Install. It seems like a lot of steps but having no problems it's now become our standard.

 

Prior to doing the above we just installed and on occasion (not always) we had the locking issue as well.