double glazing window handles

[Allied]

The handles some of my windows have come loose. One of them has even fallen off. I cannot see how they are fitted - any ideas on how to tighten the loose ones and re-fit the one that has fallen off?

[chasbo]

On my D/G handles there is a removable cover at the top/bottom of the handle base, remove it using a thin blade, under there is a screw visible. Do not over tighten, as its only a self tapping screw, and you could strip it! The one that has fallen off -- can't you see any obvious fixings, protruding screws or retaining clips etc?