Security at the windows operating system is possible by login and password, now it is clear that there are some special tools that easily can crack this traditional security, that’s why I think that WinLockr can be a good security solution to not allow cracking windows security.
WinLockr is a small tool that allow user to lock windows operating system, beside the usual screenlock you can enable the fullScreenLock a good functionality to trick users that will hide Windows interface and replace it with a fullscreen of WinLockr.
The tool you have two options the first using a USB stick to unlock so here you have two factor authentication, something you have the USB device and something you know the login and password. This combination will increase the security at the OS level.
You can download the tool at http://sourceforge.net/projects/winlockr/