@Rave
Thanks for your post. Although it didn't solve the problem completely, the links you provided were invaluable in coming up with a workable solution. Here's what happened:
1. Followed the above instructions to the letter.
2. Retried installing RoboHelp 10 trial.
3. Same results; installation stopped at 65% (Currently Installing AdobeHelp)
4. Opened Task Manager: RoboHelp 10 install application status: Running
5. Clicked the Processes Tab and sorted processes on CPU usage
6. Observed that the process: Install AdobeHelp *32 used no CPU cycles for a long time (9 minutes).
7. Cancelled the Install AdobeHelp *32 process.
8. Installation proceeded to successful completion.
9. Started RoboHelp 10 program and it seems to be working; although, I haven't really done anything with it yet.
Thanks, again.