Mountians are Black!! - Everything works fine, except when...

[marz]

FMS wrks great with windows XP. I have made a connector cord and my transmitter plugs into the mic-in on my computer. My computer isn't the best, I think I have a trident onboard graphics card.
If I set the simulator to 'no textures' everything lookes like big squares and it runs fine. When I set the simulator to 'run textures' the sky is very detailed but the mountains are all a very dark shade (almost black!!) Has anyone got any ideas? would it be due to my graphics card not being capable enough?
Thanks everyone, i'd like to hear some feedback
Marco ??? ???