Not a good idea to try a trial on the same machine that you've already got TCS installed (just general best practices). But now that you've mucked it up, I would give Adobe Support a call - they might be able to get you sorted out - it's usually a freebie. Did you try running Revouninstaller to clean up all traces of Adobe stuff before trying to install again? I'm assuming you've got full admin rights to your machine?
BTW - running the trial & installing the upgrade aren't the same experience.
Please make sure that you run the set-up from a path that does not contain unicode characters or spaces.
If problem persists, please provide us the following information so that we can identify the issue with your installation:
1) Go to Temp directory ( type %temp% in Start Menu->Run) and create a new file with the name ribs3debug ( please make sure that this file should not have any extension)
2) Make sure no other Adobe product is running
3) Run the set-up again
4) Once the set-up exits, go to <ProgramFileFolder>\Common Files\Adobe\Installers and share the installation log generated with the name Adobe Technical Communication Suite 3 (time stamp).log.gz.
FrameMaker Engineering Team