Window keys

Post a photo of the espag handle, some one might know the key to fit it.

No makers name on window frame anywhere.

 

It could be that you find any window key fits, but that said if you haven't got to many to change then replace them, quickest way...

 

http://www.handlesandhinges.co.uk/window-handle-keys/

 

When you get sorted make sure you use the locks! A lot of insurance companies these days have what they call a 113 clause in the house insurance,basically this means that if you have window locks and don't lock them they may well refuse to pay out in the event of a claim.