Resolved How do we know which program captured RS232 port??

Dear Friends;
We have many software installed in Laptop having WXP for trouble shooting purpose at machines. Communication of many devices is done through RS232. Some time it happen that a we fail to communicate with a device while everything is ok because some other software has already captured RS232 port of Laptop and it is hard for me to find out which software has done that.
Yesterday, after making communication with a PC via two soft wares, I tried to hibernate the PC but it failed to Hibernate as Com port was busy/captured while all the programs were closed. Is there any way to know which program has captured the Com port?

 

"Has captured ", (as in past tense), probably not, unless the programs leaves some kind of telltale sign/stamp in the output file.

When it's in the process of "capturing the COM port ", (present tense), you might be able to spot the culprit in Task Manager.

 

Thanks a lot for this kind help.