Gave it a shot and no change. Still got 0 pulse frequency in Mach and DriverTest works fine. One thing I am noticing as I switch from version 3.042 to version 2.63, is the load time for the program. Version 2.63 loads right up with a single system beep. With version 3.042, I double click the icon, it loads the splash screen, it gives a beep and the splash screen disappears, then about a 5 sec delay, another beep and Mach loads up. Don't know if that says anything, but it is a change from one version to another. Thanks again for your efforts. Roger