When the HTC Inspire was released, it could not access AT&T's "4G" HSPA+ network. The good news for owners is that there is now an update available for the HTC Inspire 4G that lets you use the faster data network, HSPA+.
HTC Inspire 4G users will get a notifications with instructions. You can also check for this update by going to Home > Menu > Settings > AT&T Software Update > HTC Wi-Fi software update.The HTC Inspire 4G update, along with increasing potential data speed, has Hotmail, Live, and an MSN email auto-configuration settings update, including email setup improvements.
Depending on the type of update, the update may erase all your personal data and customized settings, and also may remove any applications you've installed. Make sure that you've backed up the information and files you want to keep. Make sure your phone has a microSD card inserted. The update will be downloaded to the microSD card.
You should also make sure that your HTC Inspire is at least 40% charged. You will not be able to make or receive phone calls during the update.