I downloaded Indesign CS6 for a free trial and after the first time I restarted my computer it said that Indesign was missing a required system fonts or CMap files, so it couldn't open. Then it said to uninstall and then reinstall indesign, but when I tried to reinstall it, it said my computer needed to be restarted. After restarting my computer three times and then it said that there was an inconsistency in the installer database and to restart my computer. I have no clue what do because I can't even uninstall the software.
Click on the following link and use Adobe's CS cleaner utility to purge your system:
After that, you should be able to re-install InDesign CS6 with a valid serial number. If you're looking to re-install a free trial, you're out of luck.