That appears to be the message Microsoft puts up if the Upgrade Assistant finds something that disqualifies you from the upgrade.
Example: I was running the Win8 Enterprise evaluation version on a PC. I attempted to download Win8 pro from that. (An upgrade from the Enterprise eval. version isn't permitted.) The Upgrade Assistant returned the country/region error message. I was pretty sure that the upgrade was available in my country (USA).
If you are running the Upgrade Assistant from an activated, legal copy of Win7, I don't know what the problem is. I don't recall what information you have to enter into the Upgrade Assistant; perhaps Theog is correct about what may have been mis-entered.