>I've still got a copy of QB 4.0 and a library package from MicroHelp called
>Mach 2. The library allows access to the various ROM BIOS interrupts, and in
>running programs under Win98SE still appears to work correctly. My thought was
>using Int 13H Function 03H to write information to the appropriate sector.
>Just out of curiousity, and if I under you correctly, this won't work?

Not on NT it won't, no. NT/Windows 2000 has a Hardware Abstraction Layer (HAL). What this does is insulate the hardware from the software, so that the software has to go through the OS to get to the hardware, as opposed to getting at the hardware directly. The purpose of this design is to abstract the platform-specific details about the hardware, but the offshoot is that you can't "write to the metal" of hardware.

I'm not really well-versed on the inner workings of Win9.x, so I am not knowledgable about how Win9.x handles hardware twiddling, and I therefore don't know why it works on Win9.x. But on NT, all I can say is compile it and try it. I'm pretty confident it won't work, though. I've never had much luck directly accessing disks directly under NT.