In the case you have forgotten your pattern lock, password, or in the event that the Dell Streak Pro Gs01 malfunctions and will not let you perform a reset from the main menu, you can try the below steps.
- Turn the phone off (remove and replace the battery but do not power the phone up
- Press and hold the: Volume Up+Home+Power - you will be ushered into the Android System recovery menu
- Scroll down to 'Wipe data/factory reset' using the Vol down key
- Confirm selection by short pressing the Power or Home key
- Scroll down to 'Yes----delete all user data' using the Vol down key again
- Confirm selection by short pressing the Power or Home key
- When the wiping is complete, short pressing the Power or Home key once more to reboot
The Dell Streak Pro Gs01 should now be reset to factory defaults. Comment below with any question you may have :)