Will and os installed on one mobo work with one of the same model?

Ok, I recently bought a gigabyte motherboard from newegg, and built myself a computer. When I powered up, I installed vista home 64 bit right away... Then, when I went to check the bios, I found out that the motherboard is sort of defective. I found out that #1 my motherboard only powered up 25% of the time I pressed the power key (idk why... check connections), and that #2 cpu temp sensor was out of wack (uhhhh... in bios, it said -88c... and in realtemp/ another cpu temp monitor, it said 32c... which is probably its lowest the programs can go...).

Anyways, I am planning to rma the motherboard, but will the hard drive/ OS work right off the bat (just connecting the sata/power) without a reinstall? I figured, since it is the same model, it should work without any problems, right? Please help!