Hi Valerii,
I’m sorry that you are having such issues with the Launcher, and if you wish for assistance in investigating the root cause of your issues you can make a post on the Installation & Setup section of the UE4 Answerhub.
However, you have another option so you can still access the Unreal Engine 4 without needing to utilize the Launcher. It requires a bit more setup, but you can download the source code from Github and compile it yourself. Here’s instructions.