I have had this problem using Audacity 2.0.5 as well as 2.0 after I downgraded to see if I could fix it.
When I first installed Audacity, it started up without problems on a Lenovo laptop running Windows 8. However, it later switched to “not responding” when trying to record. It may or may not be related, but I had switched the microphone from the default laptop microphone to one on a Logitech webcam). After uninstalling and reinstalling, I could sometimes get it to run, including with the logitech microphone. I eventually downgraded to Audacity 2.0 and I thought that fixed the problem, but it is happening again after about a week.
The main thing is that Audacity seems to be starting up and shows in the task manager with 0 CPU but hangs forever and never displays anything.
I have tried deleting AppData/Roaming/Audacity, but it just creates a new directory and hangs the same way.
I spent a long time trying to find a post by someone with the same problem, but I haven’t. Is there some file I can delete when this happens to get a clean start? Any other solution?