Well, I can only say that I carefully followed standard advice in 2001 when porting this NT 4 code, to WDM, and made a one line fix in 2005 for a bug that showed up in XP SP3. Today the same code compiles builds installs and runs on Win 10 x64 with the latest WDK targeting Win 7. I might be tempting fate here, but after all the installation headaches, it ran first time. We can point out the little mistakes in specs or advice if we like - but Microsoft are clearly doing something right! This code is 16-20 years old and has never seen 64-bit architecture until today. I’m frankly quite amazed. The VS 2015 built in debugger is (to quote SoftICE) just awesome.