I'm less concerned with your CPU/board combo as I am the fact that you said you used GPU and PSU from OLD PC, and the i7 is an upgrade. First, knowing what PSU you're using would help.
As I've mentioned in earlier posts, anytime I upgrade a core component (CPU, GPU) that deals with performance, I know that power consumption and/or cooling needs to be adjusted. I'm not sure why you'd buy a Z77 board to use a 2nd Gen i7, but it is on the supported CPU list so I doubt that's the problem and I'm guessing when the Ivy Bridge i7 is available you're moving to that? Why not upgrade the other parts of your PC to reflect that?
Reboots are usually due to power and heat issues.
If you're using a PSU that's less than 500W, I'd immediately recommend upgrading to at least 650W.
Also, what CPU cooler are you using on the i7?
I wanted to get the z68 board but everyone was out of stock waiting for the z77 boards. That's why I ended up with it.
Below are the details.
Intel 2700k, 3.5 GHZ - Using Standard Intel CPU Cooler, I am not overclocking.
MSI z77a-gd65 Latest A2 Bios
Corsair Vengence, DDR3, 1600mhz,8GB,2
MSI, Nvidia GTX570, 1280MB
Transcend, SSD720, 64GB
Seagate ST1000DM003, 1TB
Samsung DVD Writer
Windows 7 Ultimate 64bit
Corsair GS700 +12V~56A, +5V~25A, +3.3V~25A
Just something else to add. As of last night it's even worse. When I press the power button now the fans spin up(the board lights up as well) and then everything dies and then restarts on it's own again and then dies..........goes into a loop.
When I did get into the BIOS it said that the CPU temp was 35'C and System Board was 25'C.
Did you get this configuration to POST outside of the case (just mobo, RAM and CPU)? Take off all of the peripherals, and just try to power it on with only those 3 things. If you have the same issues, you can narrow it down easier. My first guess would be the motherboard, but your RAM is not on the supported list for that motherboard.....http://www.msi.com/file/test_report/TR10_2536.pdf If you can get a cheap module of RAM that's on that list, try that that one by itself and see what happens.