Supported on Windows systems such as Windows 7, XP, and Vista versions, GrekSoft Advanced Screen Locker is a security application that is intended to help you secure your system from unauthorized access. Available as a free to use software application, this is a product of GrekSoft. This utility offers a second layer of security for your systems by locking the screen. This tool secures your system by implementing Passwords and Secondary passwords for logon; using a security question and answer feature; disabling the Alt F4 key, Task Manager, and Alt Tab keys; blocks shut down of the system; and makes the screen lock window full screen. These security measures are intended to prevent unauthorized user login and access.