Has anyone experienced a system completely freezeing from an application they have written in Visual Basic 6 ? I have been told that VB programs CANNOT freeze a computer, and that it must be hardware. But this specific app (which uses On - Com events) seems to freeze computers, no matter where they are installed. Is this possible ??

It's possible for system-interacting software written in nearly any language to freeze the OS. It has less to do with language, and more on what the system is required to do in response to the app, or if the app itself crashes on an unstable system like Win9x/Me. The combination of factors in programming are nearly limitless, so there's always the possibility. If the system seems to freeze only in response to the app running, then it seems likely the app is the culprit. If the system also freezes when the app isn't run or installed, then the problem is likely elsewhere. It depends on the particular problem, but hardware is not necessarily the most likely cause of freezes.

Since you are apparently trying to get data from the serial ports (ON COM), are you sure your code is not sitting there waiting for input from the COM port?

That is what is happening. I had the same problem when I first started with VB trying to write com port routines. The system is WAITING FOR THE PORT TO DO SOMETHING and it is not doing anything else or watching anything else in the meantime so it appears to lock up since it is so busy watching the port. SO HERE IS WHAT YOU DO! In your com port routine wherever it is you have your coding that accepts input from the port. MAKE THIS A LOOP if it is not already. THEN IN THE LOOP include a line "DO EVENTS" like below. Do unitl Done = False DoEvents MyData = MScomm1.input loop Now when there is NO DATA coming in from the Com PORT the DO EVENTS statement will allow input or performing another routine based upon a form button being pressed etc. This was the SINGLE MOST HARDEST lesson to learn when I started several years ago writing COM PORT routines for VB. I must have bought 5-6 books on VB before I learned this lesson. Good Luck Wayne.