Why can't it be unlocked?

If you set a pass code (or pattern) that you cannot remember, please enter the wrong password (10-20 times) until you are prompted to sign in via your google account. Please note, this will only work if you have already setup your google account on the tablet. If you have not set up a Google (or Gmail) account on the tablet, you will have to perform a firmware install, which will revert the tablet back to factory settings.

if you have a google account, you can do this option

1. When you try different patterns and unable to unlock your phone in five attempts. Then a message pop-up and shows two buttons "next" and "try again".
2. Now click on "next" button and you see two options for unlocking phone. One is answer the security question and the second option is to provide Google account details.
3. Mostly people don't set a security question. But if you set it then simply answer the question and unlock your device quickly. Otherwise check the Google account option and click "next".
4. Now provide your Google account username and password attached with your device and click on "sign in".
5. After that you are directed to choose new pattern and now you can unlock with this pattern.

if you don't have your google account, you can do the recovery option, but you will lose all your data in there

1. Power off your phone.
2. Now press Volume up, power and home button at the same time and wait until your device starts.
3. When you see logo screen release the power button and keep pressed the other two buttons.
4. Now your screen shows android system recovery and there is a list. Use Volume up or down keys to select option from the list. And select factory reset option and then press power button to let the action begin.
5. Now it asks you for confirmation, select "yes".
6. After factory reset completes, it again shows you android system recovery screen. Now select reboot option and after restart it will not ask you for pattern.

If it's an android device...
1. Enter wrong pattern 5 times and wait for 30 seconds.
2. Select "Forgot pattern" and enter your email account username and password.
3. Make sure you use the same account that was used to activate the device and double check the password by logging in to that email account in a browser.
4. If you don't have access to the original email account, you will need to do a hard reset and loose your settings and apps on the devcice. The data on the memory card will not be wiped though.
Note: if you can't remember your email password, you will have to visit the email service support page to get it reset.
also, see here...
http://www.androidtablets.net/forum/android-tablet-usage-tips-tricks/6280-forgot-your-unlock-pattern.html
or here... http://mytabletguru.com/forgot-password-pattern-unlock-of-android-tablet/

1. Enter wrong pattern 5 times and wait for 30 seconds.
2. Select "Forgot pattern" and enter your email account username and password.
3. Make sure you use the same account that was used to activate the device and double check the password by logging in to that email account in a browser.
4. If you don't have access to the original email account, you will need to do a hard reset and loose your settings and apps on the devcice. The data on the memory card will not be wiped though.
Note: if you can't remember your email password, you will have to visit the email service support page to get it reset.
also, see here...
http://www.androidtablets.net/forum/android-tablet-usage-tips-tricks/6280-forgot-your-unlock-pattern.html
or here... http://mytabletguru.com/forgot-password-pattern-unlock-of-android-tablet/

Isn't that only used when you forget your password? The most obvious thing is to check your wireless network connection. I get my laptop and the tablet interfering all the time and have to disable and then re-enable it and the connection is fixed. It may also have not been set for your account (I do not have one since those e-mail accounts are all expired) or the other account is no longer active but not deleted.

If you set a pass code (or pattern) that you cannot remember, please enter the wrong password (10-20 times) until you are prompted to sign in via your google account. Please note, this will only work if you have already setup your google account on the tablet. If you have not set up a Google (or Gmail) account on the tablet, you will have to perform a firmware install, which will revert the tablet back to factory settings.

Support Troubleshooting Guide

If you set a pass code (or pattern) that you cannot remember, please enter the wrong password (10-20 times) until you are prompted to sign in via your google account. Please note, this will only work if you have already setup your google account on the tablet. If you have not set up a Google (or Gmail) account on the tablet, you will have to perform a firmware install, which will revert the tablet back to factory settings.

Support Troubleshooting Guide

If you set a pass code (or pattern) that you cannot remember, please enter the wrong password (10-20 times) until you are prompted to sign in via your google account. Please note, this will only work if you have already setup your google account on the tablet. If you have not set up a Google (or Gmail) account on the tablet, you will have to perform a firmware install, which will revert the tablet back to factory settings.

Support Troubleshooting Guide

If it's linked to your google account you should be able to reset it. Taken from user manual:

After five wrong entries, you can reset
your unlock pattern. Tap Forgotten
pattern? and enter your Google account
username and password.
Note: You must have an active
Google account on the tablet and
an Internet connection.
If this option is not available, please
contact your local Acer service
center.

If you set a pass code (or pattern) that you cannot remember, please enter the wrong password (10-20 times) until you are prompted to sign in via your google account. Please note, this will only work if you have already setup your google account on the tablet. If you have not set up a Google (or Gmail) account on the tablet, you will have to perform a firmware install, which will revert the tablet back to factory settings.
Support Troubleshooting Guide