how to unlock HTC One M8 without factory reset.

[nebulaastra1]

Hello, I have forgotten the PIN to my HTC one M8 & it is locked.
I do not have a google account associated as it is an old phone.
I do not want to factory reset it as I need some images & documents from the phone.

If I have to use third -party app for unlock, will I need to have USB debugging on? How do I go on about it without a factory reset. Also can anyone recommend a good, tried & tested unlock app.

Can anyone please help? TIA.

 

[B. Diddy]

Welcome to Android Central! See this: What to do if you forget your phone's PIN/password/pattern - Android Forums at AndroidCentral.com

 

[belodion]

Also, hypnotic recall may retrieve the PIN.