Frame rates had started gradually falling. So I decided to give FS2002 a winter MOT. I completely uninstalled all the add-ons and fs2002. Did a defrag then re-installed fs2002. I followed this by installing the Omega drivers 40.72 now a friendlier install. All add-on scenery, FSNav and DF737 and c177 re-installed.
Installed all available Projectai aircraft using the beta installers (user friendly) and far better.
Also installed the final directx9.0 version. Ho, I also have VFR scenery installed.
The system is now running good again.
Basically I cleared a lot of stuff I didn't really need.