Thank you for your replies. The problem is, that I uninstalled everything DCS-related and tried to do a clean install, but even after installing the 6.4MB web installer, the updater stops right away.
This night, I realized, that my current installation is not a very stable one. I did some HW changes about half a year ago and did not reinstall Windows, I managed to make it somehow run, but its not optimal. I will reinstall Windows and try again. And I will report back, if there will be more problems. I doubt it, I'm almost certain, that the problem lies with the fact, that I did HW changes and now have a ragtag Windows installation.
Specs are: Intel i3-4170 3.7GHz, Gigabyte B85-HD3-A motherboard, NVidia GTX650, 2x4GB DDR3, Win7 64bit, with Intel SSD 128GB as game disk.
I will provide the logs if it fails again after complete system reinstall, but I highly doubt it.