Hi Oshyan,
Yes it is strange. I've installed all the updates since the very first preview on this machine and never had any problems.
I'm just test testing different things at the moment trying to get it to work. I've re-downloaded the update but that didn't work. I've tried to install it on another account on this machine, that didn't work. I've uninstalled, removed the TG2 folder and removed any shortcuts and then reinstalled, this didn't work either. After reinstalling I tried running the .exe directly from the TG2 folder but still no joy.
I'm struggling to think what else I can try. Any other ideas?