How do I write a program which can control a device driver?

Question

I've got a laser profiling system; the included software has a few bugs and missing features that I'd like to correct. I have the source code for this software which compiles but subsequently will not run. The device driver for the hardware is already installed (Windows 7 is the platform, though XP is a likely target as well); I'd like to write my own program which loads the device drivers and is able to control them. Is this possible? What resources are available to help the process? Is this a hornet's nest I shouldn't get involved with?

Note: I do NOT need to write a driver as it has already been written and properly installed (which is what google returns 90% of the time for my amateur searches).

Answer 1

For details you have to go to Microsoft's documents but for a quick introduction you can start here: http://www.catch22.net/tuts/kernel101

To control a driver, if you know which ioctl's the driver obeys, you call DeviceIoControl. If you need to make the driver do something that it doesn't already do, you'll have to modify the driver itself to understand another ioctl or understand more options in an existing ioctl.