I'm running a HP Probook 4540s with Intel I3-3110m processor and HD4000 graphics card.
When I load up Yosemite, just after the Apple logo and loading bar and before the desktop loads my screen glitches out for a second. I can't find anything to fix it. I've tried googling and can't find my problem anywhere.
Also, the Apple logo and loading bar are stretched. I've got my BIOS set to UEFI without CSM which apparently should fix that but it's still stretched.