Change COM Port

I Used to play old games, on two Win98 computers linked by a serial
cable. However, I got a new l;aptop which does not have a serial port
(it has 6 x usb instead). To combat this, I bought a USB-SERIAL
adapter, similar to this:

http://www.newlinkproducts.co.uk/pro...ID=4&prodID=89

However, it has assigned itself to COM9, and some of my games only
support COM1, 2, 3 and 4. My question: How can I change the COM number
of the adapter?

Thanks,
Peter