You need to enable debug logging then get a debug log for us to look at. To turn on debug logging press Windows-R and in the Run dialog type:
notepad %appdata%\xbmc\userdata\advancedsettings.xml
and click OK. Notepad will ask if you want to create the file and you should answer Yes. When Notepad opens paste the following in then click File/Save and close Notepad.
Code:
<advancedsettings>
<loglevel>1</loglevel>
</advancedsettings>
Now start XBMC, wait for it to hang, then press the escape key a few times. Press the End key on the keyboard to see if XBMC will close. If it doesn't then kill XBMC by whatever means you prefer. Now, to get the debug log press Windows-R again and in the Run dialog type:
%appdata%\xbmc\xbmc.log
and click OK. This should open the debug log in Notepad. Go to
http://pastebin.com/ and copy and paste the log from Notepad into the web site. When you've submitted the log pastebin will give you back a link to your log. paste that link here and we can have a look at it.
My guess would be a video driver problem, but hopefully the log will tell us for sure.
JR