its_andy08 Try forcing the game to launch in windowed mode. Open Options.ini, in Documents > Electronic Arts > The Sims 4, search for fullscreen (just that, not any other setting with fullscreen in the name), and set it to 0 (zero).
If that doesn't help, please provide a dxdiag. Click Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.