A small bios hook for Windows 7/8 [C/C++] -- 2

Windows operating system has some structure available which tells any software whether the connected monitor is built-in internal (Example: Laptop) or external. I want a program which I can put in start up group, so that it runs when I start my Windows session. The program should: 1. Ensure that only one copy runs at a time. 2. Read the existing monitor flag when the program starts. 3. Update (fool) the flag as the negation of the current value. So if Windows says, External monitor, it should flip the flag to say internal. This negation should be available to rest of the programs, which query this flag (This is basically the highlight of this project.) 4. I do not need any GUI for the program, however, I would like to have the ability to restore the flag to the original value when the program is terminated from Task Manager (Capture the End Program event.) This is nice to have but not mandatory. 5. Please do not use any third party software. I will accept Managed Code (.Net) solution as long as it uses Microsoft supplied libraries. 6. Obviously, I will need the full source code, and its ownership.