Many thanks for the advice on here.
I now have 3D working well from my Media Center PC and IMHO my media center pc does a better job of it than the standard 3D Blu Ray player I got with my 3DTV (which is now on it's way to ebay!).
It's certainly a lot faster anyway.
Just to let people know a tried and tested combo that works - here is what I needed to get it up and running:
1. Win7 32bit. Spec: Intel Core 2 Duo Wolfdale E8400 65W, 4GB Ram, 64GB Intel SSD
2. Zotac Fanless GeForce GT430 1GB DDR3 ZONE Edition
3. Download latest drivers from Nvidia Website which includes 3D Vision Drivers.
5. Set up the 3D in the NVidia Control Panel. Important or you just get Red/Green 3D!
6. Installed Arcsoft TotalMedia 5. Media Center Interface is a vast improvement on the previous version I had (Version 3).
7. My 3D TV is Panasonic TX-P42VT20B connected via a HDMI 1.4 cable from Amazon Basics: http://www.amazon.co.uk/AmazonBasics...2&sr=8-3-spell
Works a treat.