When I nput on the handbrake the car rolls till it seems to stop on the gears yet I can't drive off when it's engaged. How do i adjust the handbrake? (RH drive)Thanks.

It's very easy. Normal parking brake engages between 3 and 8 clicks. Raise both rear wheels on a jack, so that the wheels rear wheels can roll freely. Lower/disengage the parking brake. Remove the center console/piece of plastic between the front seats. There is one Philips screw behind each seat on the side of the console. Move both seats forward for easier access to the screws, and remove the two screws. Lift the console up from the rear toward the front of the car, and remove the plastic console from the metal retainer clip in the front of the console. There's a silver bolt in the center of the parking brake area facing the front of the car. I think it's a 17 mm socket. Turn the bolt clockwise to reduce the number of clicks to engage the parking brake, and vice versa. (I like three clicks for the parking brake to work fully). Roll the wheels at each click until the wheels don't move; that's the number of clicks on the parking brake that is reset.

Installation is the reverse of the above.

Thanks for the advice on the adjustment on the Volvo handbrake. The coming Sunday is usually a quiet day at work ( Sundays in the the Fire Brigade are not demanding days) so I'll have a go then.
Mark from downunder.

There's also the possibility that the brake shoes are shot. They're drum shoes found inside the rear rotors. Try tightening up, as suggested by Mike. And maybe when you do your rear brakes you can remove the rotors to check the shoe condition.

Thanks for the advice. I hope it's only the first adjustment as the rear discs still have a lot of life in them.
Mark.