Well, dunno what I've done.
Spitoon, holding CTRL and clicking worked, then I tried BOAC's suggestion, assuming you meant add/remove on the control panel. Couldn't find repair as an option but clicked on program access and defaults, which was set to 'custom'. I changed it to 'microsoft windows' and it now works without holding CTRL.
But when I look at the defaults again it is still on 'custom'. Maybe it won't change unless I reboot, but as I said it is now working.
Beers all round guys, thanks for the advice!!