You may need to right-click on the Tournament Director shortcut and select "Run as administrator" when you start the TD software.
There are several ways to transfer to the new PC. I would recommend: (1) installing the TD on the new PC; (2) on the old PC, run the TD and use the Backup feature to backup all of your data (select Database, saved tournaments, templates, and preferences); (3) restore the backup to the new PC.
This is outlined in a little more detail in the user manual, under the Database tab section.