The HD2 natively runs the Windows Mobile 6.5 operating system, and was released in Europe in November 2009, in Hong Kong in December 2009, and in other regions including North America in March 2010.

[8][9] The Snapdragon CPU is clocked at 1 GHz,[10] but automatically underclocks itself to 553 MHz if extra processing power is not needed.

The official unit comes with a replacement battery cover sporting a pull-out metal kickstand which supports the phone in an upright landscape orientation.

[14] Microsoft rejected it and other Windows Mobile devices, however, due to it not being compliant with the company's hardware requirements for smartphones running Windows Phone, such as a lack of a dedicated two-stage camera button and five hardware buttons on the front as compared to the three supported.

Microsoft has expressed tacit and subtle approval of such ports, nearing the release of Mango for native Windows Phone devices.

It is possible for users to call Microsoft to request an activation key, but the device is not supported as a WP7 phone and being given a code is not guaranteed.

The ability to 'mod' the HTC HD2 and run multiple different operating systems from the NAND flash or SD card has given it an enduring popularity, and this made the HTC HD2 one of the phones that could run the largest number of operating systems in the world.

Android (versions 2.2 Froyo, 2.3 Gingerbread, 4.0.4 Ice Cream Sandwich, 4.1 Jelly Bean, 4.2 Jelly Bean, 4.3 Jellybean, 4.4 Kitkat, 5.0 Lollipop, 6.0 Marshmallow and 7.0 Nougat), Ubuntu, MeeGo and Windows Phone have all been unofficially ported to the HD2.

On 23 December 2012, XDA developer zoid created a custom Debian/Ubuntu-based Pentest-focused distribution called ubnhd2 for the HTC HD2.