Tamas, I appreciate this information. I have decided to switch in a=20 different computer. Right now I am in the process of preparing this=20 system to become my print server and audio system. I will then take the=20 computer that is the print server and audio system and start using it as=20 my work system. I know that MPLAB X and the Arduino IDE work fine on it.=20 I don't know why. No, I have not done what you have suggested. I plan on=20 doing that just before I do the switch out. I have reason to believe=20 that the OS has been brought down instead of the CPU cycles being eaten up. Thanks, rich! P.S. After twenty years or so I have finally learned how to use the=20 Delay and the X-Y functions on my 465B scope. :) rich! On 10/9/2014 3:56 AM, Tamas Rudnai wrote: > If the entire computer freezes to death then my bet would go to the drive= rs > (drivers are usually not multi processed / threaded and therefore can loc= k > up the entire system). > > Other option is if a user app goes to 100% CPU utilization on all cores a= nd > your computer did not "freeze" but left no time for other processes to ru= n > so your UI becomes "unresponsive". You can load Task Manager with the > Performance tab on front before launching the app, make sure "always on > top"... > > Can you try it with other driver version or other type of USB-Serial > converter (or native RS-232)? Maybe if you use different Windows version = or > Patch Level? > > Tamas > > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .