Im sorry to here your comps too slow to play it, it runs fine on my
3 year old dog, but anyway try this as a last resort.
Select sky globe only and delete it. Relink the world and activate “mist”
That should bring your speed back up but it will look like the old V1.
I think it keeps every visable texture map in ram and I have played it comfortably with sky and aircraft textures double this reselution with only
128 meg of ram. I knocked them back down to keep the file size down.
I hope this helps.