P67 and Z77 are very closely related chipsets.
I have had good success in changing motherboards /cpu's by just installing the motherboard and booting from the old os windows 7 drive.
The easy way is to simply install your ssd in the new pc and boot to it.
You should be able to boot into windows well enough to be able to install the chipset and lan drivers that come on the cd shipped with the motherboard.
Out of half a dozen times , I was successful 5 times.
I failed only when converting a Athlon dell desktop to a intel motherboard and ivy bridge cpu.
But, to be certain protect yourself with an image copy to a external destination.
And, you might use windows easy transfer to export your files and settings.
If it turns out that a os rebuild is necessary, you can use windows easy transfer to import your files and settings. Programs will need to be reinstalled.