My samsung windowws phone won?t start.

[WPCentral Question]

The blue windows icon appear for a secound and after this the following message:
The message is: from windowws boot manger.
a recent hardeware or software might have installed a file that is signed incorrectly........

How can i start my phone again.

It is not possible to do anything with the phone.

 

[Harrie-S]

If a soft reset (push and hold the power for 10-15 sec) does not solve I fear you have to do a hard reset. See below link for the ative.
Samsung ATIV S hard reset

But be aware that a hard reset will wipe all data from your phone.

Good luck