Can't turn up resolution

[emiflyand]

Hello,
my 1366x768 HP laptop has radeon HD 7670m which should be able to give me up to 2560x1600 according to game-debate.com.
So I hook it up to my Sony 32" 1080p TV through HDMI, but it only runs 1366x768, and I can't seem to raise it in my windows resolution.
Is it even possible then? And how?

 

[Someone Somewhere]

You need to either set it to extend desktops, or disable the laptop screen. If they're mirrored, they must run at a resolution supported by both displays.