Just to keep you updated on whats going on. As its been Easter, I have not been back to the client. I will check the win.ini file as that is a likely starter. I will test all the scenarios that Allen and NTDOC has suggested, but I already know the AV is not the fault, as this has occurred at two different clients and they both have different anti virus solutions. I have tried on different computers both xp and win 7, so the profile is not likely to be the problem. But I will look at each everything, because I suspect its something about the way the domain is setup at the clients because I noticed a very interesting thing when I was testing the setdefault function at home (without the affected software). At home, if I run the setdefault function it changes the default printer and changes the tick to the new default printer. At the clients, it changes the default printer, but it ONLY changes the tick to the correct printer in the devices and printer page, if I REFRESH - ha there is a new clue ! I will be in at the client next week Thursday. Thanks