It depends on what CPU you're using. I have that exact motherboards, and have Windows7 x64 installed. And from what I see, all CPUs that goes into that socket are x64 CPUs.
It should be working without a problem.
That was the answer; Microsoft had mailed a 2002 SP2 cd which is only x86; I had explicitly requested an x64 version over the phone to the operater who as we all know are always "standing by". http://en.wikipedia.org/wiki/Windows_XP_Professional_x64_Edition
Windows XP Professional x64 Initial release date: April 25, 2005.
Moving forward; I've replaced the motherboard and CPU in the Thermaltake Overseer RX-1 case with two more 200mm fans and 120mm on bottom pulling air in from infront of the PSU. http://www.pcmag.com/article2/0,2817,2409162,00.asp
Now it can use an FDD again and IDE along with Sata2 & Sata3. http://www.asrock.com/mb/Intel/Fatal1ty%20Z77%20Professional/
Then installed Windows 7 Ultimate x64 on a OCZ Vector 256gb SSD. http://www.pcmag.com/article2/0,2817,2413648,00.asp
Since I was going in again; I replaced the PSU with a modular Rosewill 1500w. http://www.bjorn3d.com/2011/10/rosewill-lightning-1300w-gaming-modular-power-supply/
Microsoft Windows 7 Ultimate 64-bit SP1
Intel Core i7 3770K @ 3.50GHz 89 °F (Liquid Cooled) Corsair H100
Ivy Bridge 22nm Technology
16.0 GB Dual-Channel DDR3 @ 653MHz (9-9-9-24)
ASRock Z77 Professional (CPUSocket) 87 °F
2047MB GeForce GTX 550 Ti (EVGA) 97 °F
2047MB GeForce GTX 550 Ti (EVGA) 87 °F
ForceWare version 310.90
238GB OCZ-VECTOR ATA Device (SSD)
932GB Seagate ST1000DM003-9YN162 ATA Device (SATA) 83 °F
1863GB Seagate ST2000DM001-9YN164 ATA Device (SATA) 81 °F
HL-DT-ST DVDRAM GH24NS90 ATA Device
Optiarc DVD RW AD-7280S ATA Device
Realtek High Definition Audio
I picked up another small case for migrating the Asus p8z77 board too along with it's CPU and PSU and will revisit it at a later date.
Thank you all for your input. When it came right down to it and basicly just being so mad at not getting what was wanted, which was an x64 build and not realizing at the time that the Asus p8z77 board didn't have a floppy controller on it when the Barebone kit was bought from Tigerdirect; I started over. Leason learned; kits are a short cut. Do the research 1st and you will enjoy the system alot more.