ISP number/computer question Chiang Mai

[luther]

In our house, we have two PC's and one laptop all connected wirelessly to the same modem.

I was interested to see if I could watch Ken Burn's new documentary about the Roosevelts.

(Streams from the US on www.pbs.org)

On our PC in the living room, I can watch it. On the other two computers, I get the message, "Sorry this video is not available in your region."

I have not installed a VPN on any of the computers.

The PC in the living room is still running XP, the other two are Windows 7, but I cannot believe that is the difference.

All three use the same browser.

Any thoughts?