Try www.windowhandlekeys.co.uk
You can send them a photo of your handle and they will id the key you need.
Janet
May 2009
or you could take one of the other locks off one of your other windows and take it too your local double glazing firms and they might have a key that fits it.
tezza
May 2009
drill out the lock it is not made of strong steel it should come out quite easily
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix windows and doors.