Gigabyte GA-Z77X-UP4 TH Won't Recognize GTX 460 GPU

did u try it on all pcie slots but same problem?
did you update bios as the first step?

I've tried it in three different PCI-E slots and I updated first thing when I got the computer built.

vga bios needs to be checked if there is any update.
If problem still, it is probably a matter of compatibility.

I was at this point with my Z77X-D3H yesterday. This worked for me...completely unplug your video card from your sys, plug in your monitor to your on-board video port ( ya I know..you just got burnt by selecting on-board video only in bios..well..don't do that, leave it on auto. Boot up and you should have video again, do your initial setup in bios, then save and exit, go into your OS and load all your new drivers, you may have to load your vid card drivers again, don't fret..just do it. Shut down, You should be able to re-install your vid card, plug it in to your monitor, and don't forget to plug in the power connectors to your vid board ( one of mine was not in all the way and...it almost drove me nuts trying to figger that one out..I used some new 4 letter working words while in the process ( according to the wife..heh ). Hopes this helps.

sgtjeep

Turns out it was my PSU. Friend suggested that I had burned out the 12V 2x4 rail so I bought a new PSU (what luck, Newegg sent me a bunch of coupons for them ~15 minutes after the suggestion was made). Hooked everything back up and the GPU was able to be detected by the Motherboard and by the NVIDIA driver installer. So everything works great now. I'm unsure if I just did not have enough power from the PSU or if the rail really was burnt out (I don't think my system was using 550W...), but the PSU did solve this.

Thanks for the suggestions, though.

In case anyone runs into a similar issue, here is my build now:
Motherboard: Gigabyte GA-Z77X-UP4 TH
GPU: EVGA 01G-P3-1372-TR GeForce GTX 460 (Fermi)
CPU: Intel Core i5-3570K
PSU: Rosewill HIVE Series HIVE-750 750W
RAM (1+2): G.SKILL Ripjaws Series 8GB (2 x 4GB)
RAM (3+4): G.SKILL Sniper 8GB (2 x 4GB)
Drive 1: SAMSUNG 830 Series MZ-7PC256B/WW 2.5" 256GB SSD
Drive 2: Western Digital WD Green WD20EARS 2TB
Drive 3: Western Digital Caviar Green WD15EZRX 1.50 TB
Optical Drive 1: Lite-On iHOS104 BD-ROM
Optical Drive 2: Sony Optiarc CD/DVD Burner AD-7260S-0B
Case: Lian-Li PC-9F

Not running into any problems with that. I would definitely recommend not skimping on the PSU (or in my case, try to power a more power hungry machine with an older PSU that possibly could not handle it).