thanks guys but ive solved it.
i must of had a missing file somewhere so i copied the fs9 folder to a different location,
reinstalled fs and copied the folder back merging the folders and hey presto it worked.
none of my addons lost thank god.
thanks again
thanks for the response. i use active sky but ive tried the weather themes within fs9 and still nothing. i have all my cloud textures in there so its really strange.