Windows 8: Password is never accepted on first attempt

Solution 1:

I have this issue as well, and it is caused by typing your password before the Lock Screen wallpaper has fully cleared (hint: even when it looks like it's fully off-screen.. it might not be). I don't start typing until I see the password box appear, but apparently there's a delay before it will actually capture input. Hitting "shift" (or any other non-typing key) a few times usually works -- not because it helps "wake up" anything, but rather because it slows me down enough that Windows gets caught up to the user.

You can circumvent this issue by using Group Policy Editor (if available on your version of Windows) to disable the Lock Screen policy under Admin Templates -> Control Panel.

Solution 2:

try to logout from your administrator account and then try to login again ,see if u have to type password twice again. If not that means that you are pressing your keyboard before your computer completely turns on .