Try and factory reset your phone.
First, try this:
From the main home screen, tap menu
Tap Settings, then Privacy
Tap Factory data reset
Tap Reset phone
Enter your password if required, then tap Erase everything to confirm
If that doesn't work, or if your phone is frozen:
Turn the power off. If your phone is frozen, pull the battery out and reinsert it
Hold the Volume Down button
Press and hold the Power button until the device turns on
You are now presented with a menu that allows for Fastbook, Recovery, Clear Storage, and Simlock
Select Clear Storage by pressing the Volume Down button
Press and release the Power button
Now simply confirm your decision: Volume Up for YES and Volume Down for NO
All data including third-party applications will be deleted from the HTC Desire HD. Once the wipe is complete, the phone will reboot to its factory fresh state.
so backup what you need