From: Tom Mueller <tom.mueller_at_oracle.com>
Date: Tue, 05 Jul 2011 11:02:25 -0500

This problem might be related to the user access control (UAC) feature
in Windows 7.
Have you tried installing under your home directory? Are you running
the installation
program as administrator (not just logged in as admin, but actually
right click and choose
"Run as Administrator")?

Tom