HTC doesn’t want to over write your personal data and is the reason for HTC’s Desire HD for not getting Android 4.0.HTC dropped Desire HD from the list of devices getting Android 4.0 which broke a few hearts.HTC says to get the device Android 4.0 it requires to re-partition the device storage and over write the data.HTC says they found a way to get the size of the software down but might decrease the functionality and user experience.The company says it would have impacted the user experience and they didn’t wanted so.
From HTC blog
For more background, due to how storage on the HTC Desire HD is partitioned – and the larger size of Android 4.0 – it would require re-partitioning device storage and overwriting user data in order to install this update. While technically advanced users might find this solution acceptable, the majority of customers would not. We also considered ways to reduce the overall size of the software package, but this would impact features and functionality that customers are currently using. Even after installing the update, there were other technical limitations which we felt negatively impacted the user experience.
We believe an update should always improve the user experience and carefully evaluate each update based on this criteria. While we are very aware of the disappointment from this decision, we believe the impact to user experience was too great. We recognize this is a change from our previous statement and for that we’re truly sorry.