First, my PC's specs: Windows 10 Pro Asus Prime Z270 motherboard Intel I7-7700K 16GB G.Skill Ripjaws DDR4 RAM ASUS ROG Strix Geforce 1070 8GB 1 TB Western Digital hard drive 120GB SSD (containing OS) 240GB SSD I currently have GP4 installed on the 1TB hard drive. I'd like to move it to the 240GB SSD to speed up load times. However, whenever I move it there, it won't run. I have Assetto Corsa and Grand Prix Legends both on that SSD and they work fine but GP4 refuses. When on the SSD, the first time that I try to run GP4 (via GP4.exe), I get an error dialog saying "could not find any compatible direct3d devices". After the first time, I just get a black screen and have to log out of windows to be able to do anything. When I move it back to the 1 TB hard drive, it works fine again. Has anyone seen this behavior before or have any idea on how to fix it?