This cannot be reproduced on any of our working and testing machines, on any supported operating system. These problems, especially on Windows, are machine-specific issues. Try on another machine, or on a clean Windows installation with the cleanest possible software configuration—especially, without any utility software provided by your hardware vendor, and with the latest versions available for all hardware drivers. Instead of Windows 7, which we no longer support officially, I strongly recommend you install Windows 10.
These issues can be caused by utility software, such as virus protection and file management applications, running as background processes. Outdated or wrong video drivers can also do quite strange things, especially defective OpenGL implementations, which are quite frequent on Windows. Sorry for not being able to offer more useful help, but I cannot help with machine-specific issues that I can't reproduce.