The 64-bit installer (I tried 5.2.4, 5.2.4.1, 5.2.5 and 5.2) consistently hangs on Windows 7 Professional. It gets as far as the Express or Custom install form; if you choose Express, and click Next, it hangs immediately. It appears to be running another version of the installer with command line arguments; this version can't be killed, or even debugged (it complains about the loader lock).
So, is the 64-bit version actually installable?