Just make sure to save all data and personalized application and settings installed before commencing the factory setting. Performing a hard reset is only advisable if the HTC ThunderBolt 4G experiencing application problem like freezing or hang etc. This process will restore the device to its original factory default state settings.
HTC ThunderBolt 4G Soft Reset:
1). Turn off HTC ThunderBolt 4G
2). Take out the battery for a few seconds
3). Put back the battery, and turn the device on
4). Press and Hold ‘Volume’ button
5). Tap Restart
HTC ThunderBolt 4G Hard Reset Factory Setting through menu settings
1). Go to Home
2). Select Menu
3). Opt Settings
4). Select SD & Phone Storage, then tap Factory Data Reset
5). Tap Reset Phone
6). Select Erase Everything
Note: selecting YES will erase all data including apps and games installed; if you choose YES then the erasing process will start. After erasing process finish, the phone will automatically reboot and turn back on with default factory setting.
To Hard Reset to Factory Setting this can be done by button combination:
1). Turn off the HTC ThunderBolt 4G , press and hold ‘Volume Down’
2). Then briefly press the ‘Power’ button
3). Wait until the Android logo to shows up
4). Release the Volume Down button
5). Press the Volume Down to select Factory Reset
6). Press the ‘Power’ button
Once the wipe is complete the HTC ThunderBolt 4G will then reboot and it will restore back to its original factory settings.