PCIEX16 slot not working

[parp8654]

I have a gigabyte z77-d3h motherboard and have been running a gtx 660 in the PCIEX4 slot for several years. I just got an MSI 1060 6gb card for christmas and want to upgrade. Due to my case size, I cannot fit the new 1060 into the PCIEX4 slot, only the PCIEX16 slot. However when the card is in the PCIEX16 slot my pc won't boot past the windows 10 logo, it freezes there. The same thing happens if I have my old gtx 660 card in the PCIEX16 slot. I'm unsure if the 1060 will work while in the x4 slot as I'm unable to fit it there. I'm not sure how to even address this problem. Is the slot faulty? Do I need to do something with BIOS? Should I just buy a new case that will let me fit the 1060 in the x4 slot? I'll provide any info needed, I'm just at a loss as to where to start.

 

[Dark Lord of Tech]

Maybe a BIOS update or try disabling Secure Boot in the BIOS.