Is it possible to run Freesat + HD from a Sky HD dish. Already have Sky HD and want to connect Freesat to another TV?

With a Quad LNB yes - I could ask why but I won't.

The OP already has a quad lnb. Just needs a second pair of cables connecting.

I had such a setup for quite a while. I was using the Sky box as a freesat from sky box. I recently bought a second Humax 500gb box and dumped the Sky.

All you need is a quad LNB which are available from many sources and two runs of twin cable as each box will require two feeds from the dish. The quad LNB will have four connections.

While you are at it you might consider an Octo LNB for future proofing. They are available from as low as £17 on E**Y.

Your emphasis on "HD" is not relevant as the same setup applies to both SD and HD reception.

As I already said, if the OP has a Sky-HD box he will already have a quad lnb.

Because a Sky box only has two tuners and there's so much content available that sometimes you need more. This is especially true of HD content because there are no +1 channels. It's quite common for us to have two PVRs recording at the same time and not unheard of for us to call on the services of our Freeview PVR as well.

I've got a total of 3 pvr's ( 2 running from Quad LNB Sky+ dish) . the more the merrier LOL
Thinking of getting a foxsat + 1TB disk too perhaps, although the 'free' HD box from sky would cost the same over 2 years I guess.