Can't unlock Asus tablet / Text to Speech issue?

[AC Question]

My Dad is unable to use his Asus tablet. He has a slide unlock function on the screen but it is not working. I have tried a soft and hard reset but neither work as indicated in online tutorials. I think the problem may be that he has activated a Text to Speech function without realising. I cannot work out how to use the slide unlock on the main screen and the function may also be preventing the factory reset from working. I am not sure of the exact model of tablet but it does not have Windows 8, probably Windows 7. Any help gratefully received! Thanks.