I have the same problem. My computer crashes and restarts when I open Mach3. This started happening when I run the driver test. At initial install, I can open Mach3 with no problem, but I do not have motor controls. After running driver test, the driver got installed, and the blue screen of death started happening whenever I open Mach3. This still happens even after I installed the special driver. I am running Windows 7 32bit on an old computer (3Ghz Pentium D, 2gb ram). I really hope someone can help me. I cannot find any solution to this problem anywhere. Please help. Thank you.