Hi Iain
You haven't mentioned which OS.you have but I would bet it was vista or win7.
This link covers the problem you face an all available solutions it is an old bugbear that has bothered us for some time. This will only work for win 32 bit as there are no 64bit drivers available.
http://www.meade4m.com/index.php?/to...dows-7-ver-55/