Since PGP Corp was bought out by Symantic I've not updated my old version which still happily encrypts my sekrit files but no longer works with Email, something blocking it in Win7 I guess.
So I finally got around to installing an Open Source PGP, which seems to be working after the usual installation glitches.
First I needed GNU Privacy Guard for Windows. It's installation wizard rejected my existing key, but it was willing to add it once up and running.
Then I added Enigmail, a plug in for Thunderbird, told it to check my Address Book and there were my security minded friends again: