Colin Haig

That made me chuckle. Santa Barbara Instrument Group literally invented self-guiding cameras and patented the idea back in the late 1990's. They were immensely popular - the ST-7 was the first in a long line of many self-guiding cameras. This went on through to the STL-series with larger sensors and larger guide chips, and then on through to the late 2000's when narrowband filters became popular with the rise of light pollution and the reduction in manufacturing costs of the coating technology to make these interference based filters. Eventually SBIG and later Diffraction Limited (the owners of SBIG since 2014) developed self-guiding filter wheels, so that the guide sensor was ahead of the filters, allowing for more guide star choices.

Best bet is contact Diffraction for help: https://diffractionlimited.com/ Version 5 is over a decade old. You'll need to supply the DL folks with your serial number and email address.

Hi Grzegorz, usually this is caused by Windows Power Management, USB selective suspend. The USB goes to sleep to save electricity; this causes the communication with the camera to fail. If you tell Windows to disable USB Selective Suspend, and turn off the ability to power off the devices in Device Manager, this usually fixes it. There's a detailed explanation over on the Diffraction Limited tech support forum here: Prevent Disconnects - Disable USB Selective Suspend