This issue can't duplicate, Maslobojik. Meanwhile, it also can't duplicate on most computers.
We suggest: download a portable version of 4.9.3.1000 and install in a different disk.
(For example, if you installed installation version of 4.9.3.1000 in C disk, you can install portable version of 4.9.3.1000 in D disk.)
Then duplicate the issue in portable version, meanwhile open windows system task manager, check the CPU occupation and RAM occupation. It would be better to take a screenshot and share with us.
Thanks Maslobojik and looking forward to your reply.