Bill:
I just ran through the same Chinese Firedrill as Lowcountry and I assure you
that the web pages that got me to download WDX64 did not explain what the
"64" referred to and how I tell I am only running at "32" whatever-they-are.
My WD told me there were upgrades available. I went to the page and it was
not clear what I should do. I did not find anything that said "Here is the
update for Windows Defender that the program nagged you about". I fumbled
around and clicked on some things and apparently downloaded something that
verified my version of XP was legit and then something else that seemed to
take me to WD version 1.1.1593 even though the web site said 1.1.1592 was the
latest version. Anyway when that was all done, I noticed this thing at the
bottem of the page that said others had downloaded Windows Defender X64, I
went to that page and read the description, sounded like a better version
that the beta version I had so, according to the instructions, I uninstalled
Windows Defender (beta), downloaded and tried to install X64, got the message
that indicated my Athlon Processor couldn't handle X64, but not why. There
was no hint on the web site as to the problem, so I came to this discussion
site and there in not-so-clear terms was a discussion of my problem. Now I
have to downlaod and reinstall what I had half an hour ago. Thanks for the
confusion MS!