That's not enough information.
Tell us your operating system first, Windows or Mac and which version, and which graphics card.
Then tell us what you have done so far and if you get an error message or something of this kind.
Fenja
PS. Your posting is marked as solved (green check mark) > that's misleading.
You should add "not solved yet" to your heading, if that's possible.
Or you can delete your posting and write it anew.