On October 7 when Windows phone was launched, the HTC Touch Diamond2 was made available with Windows Mobile 6.5 from Telstra.

Before we launched 6.5, Optus and a lot of open channel/retail partners were selling the HTC Diamond2 powered by Windows Mobile 6.1. If you own one of these then good news – the official Windows Mobile 6.5 update is available.

Click on this link http://www.htc.com/au/SupportViewNews.aspx?dl_id=768&news_id=365 and follow the instructions that HTC provide.