Error: run time 8018

[win_832001]

Hi all.
I am working on the programming about the microcontroller and the vb using serial port. The problem is when I use the program in my PC, it works.
But, after I run the program on the other pc, it did not work and got an error which is:

run time 8018
operation valid only when the port is open

Thanks in advance.

[Al42]

That's usually caused by something else using the port, so your program threw an error (which you told it to ignore) when it tried to open the port.

[win_832001]

tq for the reply..actually there is not any device used at that serial port except my device..and i have something weird using the port which is when i just insert the DB 9 cable into the PC serial port the LED from my external circuit has flashed..that's mean the signal has been sent eventhough i did not sent the data from my program..

how can i overcome this problem..tq..

[Al42]

Which means that some program is using that port.

Check for things like a Palm or PocketPC link program - even if the external computer isn't connected, those programs keep control of the port.