Thanks TuFun, will give that a try.
FSX68, don't worry I'm using SweetFX with the GUI and the remove button does a good job of cleaning the files out. I'm also pretty familiar with FSX's file structure so can usually sort any problems out fairly quickly without having to resort to re installing.
Also heres my Nvidia Inspector settings
Antialiasing
Antialiasing - Mode = Overide any application settings
Antialiasing - Setting = AA_MODE_METHOD_SUPERCAA_64X_4v12
Antialiasing - Transparancy Supersampling = 2x Sparse Grid Supersampling
NVIDIA Predefined FXAA Usage = Disallowed
Texture Filtering
Anisotropic filtering mode = User-defined / Off
Anisotropic filtering setting = 16x
Texture filtering - Negative LOD bias = Clamp
Texture filtering - Quality = High quality
Texture filtering - Trilinear optimization = Off
Common
Maximum pre-rendered frames = 1
Power managment mode = Prefer maximum performance
Vertical Sync = 1/2 Refresh Rate
In FSX Graphics
Target frame rate = 30
Filtering = Trilinear
Anti-aliasing = unticked
It runs buttery smooth with no shimmers, blurries or stutters at a solid 30fps
Not bad for an old system
I use the same settings with the same results in P3D 1.4