[otrs] FQDN

Hello All, I'm having a problem changing the FQDN of our OTRS system. I had copied the mysql folder from the initial PC I set the system up on, knowing that I could change the few settings for the new PC. In SysConfig>Framework>Core, the FQDN is set as flynne.example.com with flynne being the old pc. I'm trying to change it to horizon.ourdomain.com, but each time I hit update, it reverts back to the previous FQDN. Is there another way I can change the FQDN by going into the mysql files? I don't know too much about sql but I'll give any suggestions a try. Thanks Emily