Make sure you REALLY have no kind of firewall or antivirus program running in the background. I had the launcher crashing problem as well and it worked again when I stopped Anvir which is an extended task manager that watches internet connections and other things.
Microsoft Security Essentials does not seem to cause any trouble, so get it for virus protection.
I have no firewalls or antivirus software running, of any kind, including windows. I played for about a month, no problems, until Windows 7 Service Pack 1 came out, which I hadn't played that week, so I don't know whether to directly attribute the problems to it or what.
I've managed to fix the Gameclient.exe crash issue by uninstalling Windows 7 Service Pack 1
This has solved that for now.
To list what I've tried before doing that:
I tried rolling back the nvidia drivers and doing a clean install with no 3D drivers. This failed.
I tried Removing active and inactive antivirus programs, including windows firewall and antivirus. This failed.
I tried Reinstalling STO and using the options to change proxy, force verify, safe mode, Show all games,
disable on demand patching, each individually and combined. This failed.
I tried running as administrator and using compatibility modes. This failed.
Despite fixing the crash issue, I've come upon a new problem:
This crash happens after I'm in the game, when I'm battling the Borg in the Eti whatever sector, the initial planet you go to early on to fight borg.
It's from shooting a borg ship or a borg ship shooting me.
Win32/M_P_Explosions_Space3.Fsb is the file that fails to load properly.
Google pulled this thread up as the most recent, so apologies if I'm necroing.
I have the exact same issue. Thought it might be my firewall. Turned it off. Thought it might be Avast. Uninstalled. Tried all the suggested short-term workarounds. Tried running as admin. Is this just a recurring problem that crops up every update or so? Just got a new graphics card and was looking forward to actually being able to see the game as it's meant to be seen.
Instead I am seeing gameclient errors. Can't really complain too much about problems with a free game, I suppose, but it's making me regret the $40 I spent on ships and costumes.