Hi waner -
From the conversation that you and have had it sounds like there is an issue with some of your Visual C++ Redistributables. First thing I would ask you to try is running Windows Update and make sure that there is no available updates. If there is download and restart you computer as necessary until you have no updates. Then Open the Launcher and Re-Verify the Engine Download.
If after you do both of those things you are still having an issue, then just after reproducing the freeze and I am assuming after you either crash a runtime as above or have to CTRL-ALT-DELETE out of the engine, open Windows Event Viewer and save out the last few errors and criticals messages generated by your PC (you can see Microsoft’s website for the instructions for Windows Event Viewer.) Once you have saved out those files, them up and post them here so we can take a look.
From your descriptions above though I would imagine that updating those redistributables will fix the issue.
Thank You