How do I find out what program/process is using my com1 port?

[newbie]

I have an existing program that use com1 port for communication under
WinXP SP2. Recently, when I start the program, I got "open com port
failed" message. If I try to access com1 port with HyperTerminal, I got
message that indicates the port is being used by another prog. Is there
a way to find out what program is attached to the port?
TIA

 

[JS]

You need to find the specific system process that's using the COM port
(there are also a lot of sub-processes).
I have not used this tool for your specific issue but see if it helps.
To do this try Process Explorer:
http://www.microsoft.com/technet/sysinternals/SystemInformation/ProcessExplorer.mspx

Once you have Process Explorer installed and running:
In the taskbar select View and check 'Show Process Tree' and 'Show Lower
Pane' options.
(This will provide the detailed info you need)
Then click on and expand the 'System' process and identify the
sub-processes.
Click on and Highlight the sub-process of interest, right click and from the
options listed select: google, This should display what out there on the web
about that process.

Note: some entries like Explorer, System process and svchost may need to be
expanded to show the detail, (sub processes), in this case click on the +
located to the left on the entry.

Another tool to look at is named: What's Running
http://www.whatsrunning.net/whatsrunning/main.aspx

JS