How can I download or get a trial version of 64-bit Autodesk Navisworks 2009? The Autodesk website has only 32-bit version to download.

I downloaded it and installed on my 64-bit workstation running on 64-bit XP, it worked the first time but can't find the AutoCAD 2009 plugin, that's mean no .dwg support.

Then I uninstalled it and reinstalled, it won't let me run the program and I can't use 000-0000000 serial number....

Please helps!