Trying a "cache wipe" - it will NOT clear your personal data.
1. Shut down device
2. Hold Volume Down and the Power buttons until you boot into the HBOOT menu
3. Select the Recovery option using the Volume button
4. The white HTC screen will appear followed by a black screen
5. It would say failed to mount SD four times - wait until it turns into a red triangle with an exclamation point
6. From there, hold down the Volume Up and then press the power button
7. A stock recovery list should appear - select wipe/cache