I've just installed Mathematica 10, on Windows 7, but am having problems with the notebook freezing. Specifically, the problem seems to occur when typing functions, at the point where the predictive interface will try to suggest an autocomplete for the function. The notebook will freeze for 30 secs or so, and the window will report "not responding". It resolves itself eventually, presenting the autocomplete menu, but the delay makes using MMA 10 practically impossible.
The kernel seems to be fine.
Is this a known bug?