Dell Optiplex 320 Screen Distortion

 Hi, I am new to the forum. I just acquired three Pentium 4 Optiplex 320’s from a computer lot. I know they’re very old but I’m a computer reseller and I know I can try to get them Windows 10 worthy and be intended for office use. Two of them boot up great and I have Windows 7 32 bit installed on them now but this screen distortion issue comes up on the boot loader screens with the logo on both sides of the screen on the picture. It does it on both of the machines. Other than that, no flickering or distortion at all inside Windows! Everything else works perfectly fine! I’m guessing it has to do with the ATI Vista driver. I know Windows 7 or Windows 10 isn’t supported on that model. How can I solve this? Should I install an older Vista driver? Why is this happening? Suggestions and answers are welcome, Thank you!