Thank you for the reply!

Sadly, adjusting IE and compatibility didn't help. Antivirus and windows defender are turned off.

Everything works perfectly on another laptop, so router or ISP shouldn't be the problem.
Haven't yet connected directly to the modem, though.

I also tried installing trial version as an experiment of sorts and it crashes with "C++ runtime error, abnormal program termination" message (no digit code).
Could I have some essential component missing?

I'll try analyzing launcher with event viewer and some tracing software later. Perhaps this will narrow the search.