Hi,
You don't state the model of your Skytex tablet so hopefully this will still be of some help to you. Go to the second option described.
''Be aware that a hard reset will erase all of your downloaded apps and user data and will restore your tablet to a factory default condition. It will be like when you first bought it.''
If you can, before you perform a hard reset ensure that the battery is charged. Do not perform a hard reset with the charger connected.
http://www.mobicpc.com/how-to-hard-reset-skytex-skypad-alpha-2-to-factory-default-setting.html
Be patient it takes a few minutes to complete.