>I have a program which is using mscomm32.ocx to read the com port. I just compile the latest version program and run into my pc which previously installed. when i run it, it come out the error msg, error 410387 :class not register. but when i run the old version, it can be run. why?

Make sure you have the same version of the ocx where you compile and where you run the program.

You can use AGETFILEVERSION() to check this.