You can hard reset it you need to, check this out.
This first method can be used if the device still functions enough to get through the menus.
1. Open up your apps list and go to Settings > Backup & Reset which is under the Personal section
2. Press Factory Data Reset
3. Press Reset Tablet
4. If the device is password protected, it will prompt you to enter your password, pin, or pattern, etc. Press Erase Everything to finish
This method must be used if the device is no longer functioning at all.
1. Turn off the device if it is turned on
2. Press and hold the Volume Up, Volume Down, and the Power Button at the same time for about three to four seconds to turn the device on, if done correctly you’ll see an Android lying on its back
3. Use the volume buttons to navigate to the Recovery Mode option, and press the Power Button to confirm your choice
4. The device will restart, and after a few minutes the device should boot to a screen showing an Android with a red triangle, press and hold the Power Button and Volume Up on this screen
5. Use the volume buttons to navigate to Wipe Data / Factory Reset and press the Power Button to confirm your choice
6. Use the volume buttons to navigate to Yes and press the Power Button to confirm your choice
How to Hard Reset the Google Nexus 7 Tablet