I tried to install Inventor again. This time I got past the license page, and agreed to install pretty much everything. According to ZoneAlarm, there was much accessing of the Internet.
In between installing a DVD worth of software, I monitored the tree cutters, who were taking down a too-tall London Plain tree in our back yard, which also, according to the arborist, is the cause of much allergy suffering. Indeed, the six masked and goggled tree cutters were suffering from the dust given off by the tree's leaves, bark, and seeds.
Every so often, I'd return to my office to give Zone Alarm permission to let Inventor or one of its siblings access the Internet yet again. The install was nearly done. One more time I gave permission to Zone Alarm, but this time the installer was too impatient.
It complained that things were taking to long, and began uninstalling. Wait! Stop! Well, it didn't uninstall everything. The summary screen listed:
* Inventor Professional 2008 -- succeeded
* Vault 2008 -- succeeded
* Data Management Server 2008 -- failed
* Content Center libraries -- failed.
It looked like enough got installed for me to try out the software. I double-clicked the Inventor icon on the desktop, and it started up. Success!