I don't do Windows, but here is a script I use to record conversations on my Linux box. Perhaps it might help give you some ideas.
#
# This script records a phone call in progress from the specified OBi device
#
USER=user
PW=/change/this/to/the/password/of/the/user/account/on/your/OBi/device
DIR=/path/to/the/directory/to/save/recorded/conversations/in
IP=192.168.0.5/user # change this to whatever IP address is assigned to your OBi
[ X != "X$1" ] && FILE="$1" || FILE="${0##*/}-$(date +%F@%H:%M)"
cd "$DIR"
case "./$0" in
*/ph1 ) PORT=0 ;;
*/ph2 ) PORT=1 ;;
esac
exec wget --user="$USER" --password="$PW" --output-document="$FILE" \
"http://$IP/record.au?port=$PORT"
Install this shell script in a directory searchable by your PATH variable, and link it as both "ph1" and "ph2". When I'm on a call and decide I'd like to record it, I type "ph1" or "ph2" on a command line screen, depending on which line I am on. The recording continues until I cancel it or hang up. Optionally, I can specify the name of the file as an argument to the command itself; otherwise the script creates one based on the current date and time.
A few caveats: This was tested under the Korn shell, but it uses standard shell constructs and should run correctly under any modern shell. It's only been tested with my OBi202 which is running build 5135. It does support recording two conversations simultaneously. I chose to use the user account to initiate the recordings. I did this because it is more restrictive, but you can also use the admin account if you prefer; just change the USER variable to "USER=admin", specify the admin password, and remove the "/user" from the IP address. Since the account password is recorded in the script, you should probably restrict read access to protect your OBi's access credentials from prying eyes. (BTW, you do know how to set the User account password, right? It can be done under the 'System Management' -> 'Device Admin' page on the OBi.)
My Easter present to all you Linux folks reading the forum. Enjoy!