The hot fix for IE7 installer looks for the registry key:
to determine if a user has Autodesk DWF Viewer 7.0. Some users do not have this registry key. These users get an error message:
If you have this problem, you can try creating a dummy key and reattempting the install. I solved the problem for myself by uninstalling the DWF Viewer and re-installing by visiting the Autodesk web site. Once the hotfix is properly installed, you should have updated HTML files found in C:\Program Files\Autodesk\Autodesk DWF Viewer\EComposite:
and the version information on C:\Program Files\Common Files\Autodesk Shared\dwf common\AdView.dll should be 22.214.171.1248:
We are investigating why some people have this registry key while others do not. Thanks to all those who have alerted us to the issue. This will be corrected in the nonBeta version of the fix which will be released as part of an overall service pack in November.