I'm running 64bit Win 7 Professional. I upgraded from the last version to 0.6.07 with no problem.
The problem may be with some software on your system.
Try using the
free version of
Revo Uninstaller to uninstall Calibre. Do the "
moderate" unimstall.
http://www.revouninstaller.com/revo_..._download.html
This has removed troublesome software for me in the past (software using SQL).
If that doesn't help then it just may be something on your computer. Or it may lie with some 0.6.16
to 0.6.37 problem.
Next step is to see if you can "go back" to the older version if it worked for you