There are two ways of using multiple instruments, either in the same instance of Picolog or by running different instances of Picololg.
To use the first method tick the 'Multiple converter' box on the 'Recording window'. Then add the converters and set the channels (parameters).
The second method is slightly more complex.
Open Picolog in the usual way. This opens the first instance, then to open the second:
Start | Run
enter in the 'Open' box .... c:\pico\plw32.exe second.plw
c:\pico is the default path to the installation, if you have not used this then enter the correct path name. This will then start another instance, one this has worked, you can create a shortcut. On your desktop, right click the mouse:
New | Shortcut
enter the same text in to the command line, again adjusting the path name if necessary:
Click next and enter a name for the shortcut.
The above steps can be repeated many times to create different instances of Picolog, all that needs to be done is change the name of the .plw file.