new 7.6 iTunes64Setup.exe "The installer encountered errors before iTunes..

I am using Vista 64 bit. Used 64 bit IE to download the proper file
iTunes64Setup.exe
from
http://www.apple.com/itunes/download/

But I get this error when I try to install:

The installer encountered errors before iTunes could be configured.
To retry these operations at a later time, please run the installer again.
Click Finish to exit the installer.

I tried installing when logged in as an administrator, and again as a a user, again same results. I tried uninstalling 32 bit iTunes 7.5 and rebooting, but the issue still remains. I manually wiped away the
c:\Program Files (x86)\iTunes
directory (had only one file in there after uninstall), same problem.

FYI, this is just my secondary machine, so I'm not worried about loosing anything. So registry cleaning likely. But first, I'll try installing on a pristine 64 bit Vista virtual machine, just to see if the installer binary itself runs correctly on a machine without a history of iTunes 32 bit.

Is this a known issue with 7.6 64 bit? Is there a workaround?

There are many search hits for similar errors under 7.5 32 bit, but I seem to be alone with this error with 64 bit installer, for now...