There is alot of info out htere referring to this sort of work, like the famous "Controlling LED's with parallel port article in Codeproject which is years old, and other stuff that is also outdated. Looking around here there are some tidbits of info, but no clear direction for someone like myself who is not an expert. I know about the functions like CreateFile() and DeviceIoControl() , but it'S not obvious for me to know how to use them. Anyone already done small tests with just turning on/off LED's on the port and have some code example? I have theinpout32.dll, but when I try to register it (regsvr32) it tell me it's loaded, but the DLLRegisterServer Entry Point was not found...so the little codeproject example, which looks really like what I need, will not function. Any help out there please? Thanks!