For Thailand they use Thailand Orange or DTAC. Here is how to manually select a network:
Manually Selecting a Network xxx8211; While traveling you may need to select a different carrier or technology to be able to access data features. A list of carriers that provide data services are available at International Roaming
- Click Manage Connections > Mobile Network Options.
- Select Network Mode and click the trackball.
- Select GSM to allow connections to GSM networks only.
- Select Network Selection Mode and change to Manual. A list of available carriers will be presented.
- Select the carrier that offers data service according to the link bove.