Try unlocking your Windows 10 device remotely if you get this message: "This device has been locked for security reasons. Connect your device to a power source for at least two hours and then try again." The key is to reset your PIN through account.microsoft.com. If you use remote unlock, your logon PIN will be protected by Windows instead of your device's security system.
Sign in to account.microsoft.com/devices.
Find the phone you want to lock remotely in the list, and the select Find my phone.
Enter a new PIN, and then select Lock. You'll now be able to unlock your phone with a new PIN.
To go back to having your logon PIN protected by your device’s security system, make sure the device has been on for at least 2 hours. Go to Settings > Accounts > Sign-in options and select I forgot my PIN. Enter your Microsoft account info, verify your identity, and set the PIN for the device.