I am having the exact same problem with you and your YouTube situation is EXACTLY what I get.
I just built my box a few days ago so this was incredibly frustrating for me to experience.
My build is:
• GA-Z97X-UD5H Black Edition Rev 1.0
• I7-4790
• DDR3 2*8GB (Kingston Hyper X)
• Hard disk AHCI mode in:
• 1 x Crucial M550 CT128M550SSD4 128GB in port M.2
• 1 x BR/DVD drive (can’t remember the port but it was NOT the SATA ports that are 'blocked' when using the M.2 card)
• Windows 7 Pro SP1
All other drives are removed for this scenario
The bios version was F4 but was upgraded to F6 but still the same issue.
I am looking at a potential solution in this forum:http://forums.tweaktown.com/gigabyte/58623-ga-z97x-ud5h-bk-sata-issue.htmlIt looks like updating the BIOS to the F7e Beta may work. I haven’t tried yet as I only just found this out.
The other potential solution is to install Windows 7 x64 in UEFI. Not sure why they discussed this as I thought the F7e beta solution worked but here are the details:
“To install Windows 7 x64 in UEFI (gpt partition drive) the easiest way I've found is to use a USB stick with the Windows install files on it. Then use the boot menu (F12) and select the USB stick. Sometimes I've had to set the bios to boot UEFI only. I use Rufus to format and place the Windows ISO on the USB stick. Rufus - Create bootable USB drives the easy way
HTH. There is lots of places on the internet with helpful information about installing Windows x64.”
I hope this helps and I’ll let you guys know if it works for me as well.
Note: I just noticed in the header that you have a different MoBo from me so please select the correct one for your system from this list:
http://forums.tweaktown.com/gigabyte/28441-gigabyte-latest-beta-bios.html