I tried resetting our Samsung Galaxy Tab 10.1 today using Settings -> Privacy -> Factory data reset. The device refused to reset itself without the Samsung account password. Fortunately there’s a way to reset outside of the OS.
Shut the tablet down.
Hold the volume down button and press the power button to turn the tablet on.
Release the power button when the Samsung splash screen appears, keep holding the volume down until the system recovery screen appears.
The Android downloading icon should be blinking, use the volume down to select factory reset option (large box next to the small Android).
Press volume up button and wait for the Android system recovery to start.
Use the volume down button to select “wipe data/factory reset”.
Confirm selection with the power button.
Use the volume down button to select “Yes — delete all user data”.
Confirm selection with power button.
Wait while the device resets…
“reboot system now” should be selected.
Confirm with power button.
Wait for reboot.