k1114 :
Once you log into your pc, in your logic I'd have pw prompt for doing anything on my pc. That's what uac is for, not the password to log into the local account. The desktop is completely the same with or without a password once you get to the desktop.
Not at all....
1) UAC won't work as intended if you're on an administrator account, if the system becomes infected the malware just starts up automatically with your account.
2) For regular use, you ONLY need to log in once. Only use that modifies system files will require a password, and no regular use software should ever do that!
3) The point is that the use is the same... The only time you will ever need a password is logging in or changing system settings (not user settings like brightness, your background image, etc, only things like adding a new program ). The effect on the user is minimal, but it prevents malware from doing anything without your consent.
4) Disabling the password at boot (which is possible) is a security risk that just isn't worth it, for the above reasons and:
5) If your device is ever stolen, passwords will help protect your data a small bit. If you have something with Bitlocker though, it will secure your data enough that you don't have to worry about thieves stealing your credit cards and banking information on top of your actual computer.
And interestingly enough, auto-logon doesn't actually make you boot to desktop (idle) any faster than typing in the password yourself, usually you'll be limited by delayed services regardless.