Bad news sorry, most of the memory blocks and DOS interrupt tricks that old school 13h and modex programs used won't work under windows. However it is possible to still use the same techniques. If you allocate a framebuffer (similar to a double buffer), you should be able to then use SDL, DirectX or OpenGL to draw a textured quad to a full screen application. On the other hand it may be just as easy to look at OpenGL, DirectX or SDL directly - they make everything so much simpler, and although they take a while to learn it's nothing too hard and there are plenty of websites offering assistance. Most video cards still support these resolutions. If you can keep you head when all about you Are losing theirs and blaming it on you; If you can dream - and not make dreams your master; If you can think - and not make thoughts your aim; Yours is the Earth and everything that's in it. Rudyard Kipling

Thank you ... Im not using Dao so I hope that last part of code does not apply to me. And I though that all asserts are turned off in Release version (through #ifdef _DEBUG) ... sigh, so looks like its hopeless

Try using RunAs to execute it with Admin priveleges. "Please don't put cigarette butts in the urinal. It makes them soggy and hard to light" - Sign in a Bullhead City, AZ Restroom

Here's an article that can help you get started... you can probably adapt it for your needs. Avoiding Multiple Instances of an Application[^] Even a broken clock is right twice a day.