Thanks for your help, I didn't realise I needed a driver! But I think I may have come across another problem, I ran a program to detect activity in the COM ports and my computer's not detecting my telescope. The manual does say to have the telescope attached to the computer via a RS232 port and cable, but my computer doesn't have that kind of port, so I just joined the RS232 cable to a USB cable and plugged it in. Is there any way around the connection problem?