is there any way make a program run before windows starts. i've seen one of my friend doing this . he wrote a C program, it runs just after he starts the PC( after the post screen ). can any one tell me how to do this . just want to know how to do this.

You won't get a programme running until the core components of the OS are up and running. The only thing that runs after the POST is the boot loader. If you want to write you own boot load you can do. But it's a complex process and you will need to do a lot of reading. The other alternative is to write a programme to "run as a service". It then get loaded as part of the operating system and runs before the desktop or any user programmes start. Stuart

Another way is to put it on a floppy like the hard drive diag programs. But any thing you compose has to be able to stand alone. I may be crazy, but I'm not stupid...

Even a floppy disk based diag programme laods some kind of OS. Usually a cut down version of DOS or something similar. Stuart