If Windows 10 has chipset drivers for your motherboard then you should be fine. I could not find any drivers higher than Windows 7 for that motherboard on the EVGA download page.
 
If you have two EVGA 660ti cards in Windows 10 this should work provided that you have chipset drivers for your motherboard and you should also be using the latest Windows 10 video card drivers from NVIDIA.
 
 

these are the latest drivers for the board:
 
http://www.nvidia.com/dow...sults.aspx/30655/en-us

i installed windows 10 on evga 730i/9300 board and it works

Don't feel bad , I have crashes & freeze ups on my 780i sli board too . A fresh install didn't help either .

I have 10 installed , a fresh one . Windows fubared the upgrade when I tried to do a reset . So I wiped her and did a fresh install with all the latest chipset drivers . The only war I can keep it from tdr crashing is to remove the nvidia driver ànd use the generic non-nvidia base driver . I then can watch video without crashing . After a lot of googling it seems I'm not alone with this issue . It seems to be hit or miss with driver and card combos . Nvidia knew about the drive issues with 10 back as far as January of this year . I might just pull the drive and install 7 back on another one and see how it goes . I'll loose 1080p and 5.1 audio with Netflix , but oh well...

I got a 780i. I upgraded to Windows 10, and I'll crash atleast once, if not 2-3 times an hour while playing full screen games. So far it's only happened with two games, but it's a pretty consecutive crash within the hour. It's getting pretty frustrating.
 
I had old drivers for the GPU (GTX 570) so I updated those, crashes still occur. I just reinstalled Windows 7 a few months ago, so should have latest drivers for board.
 
Still ongoing. My solution? Play everything windowed mode and no crashes. It's not a great solution, mind you. I get the feeling that the 780i was pretty advanced in the day, introducing a lot of cool stuff and trying to be ahead of the curve--which is why I bought it. But going on...8 years since my build, the board is really showing it's age and I've had random issues I have to contribute to to a collage of weird motherboard issues. It's served me well, but the time is coming.
 
Q9450 Penryn if anyone is curious.
 
 

Not sure where to go or such, but figured i'll keep posting here as an update.
 
About two-three times a week I'm getting crashes doing general computing too. Not limited to fullscreen gaming or even gaming apparently. Happens enough times with doing a bit of everything to know it's not a fluke. Both screens go dead, continue to hear sound for about 5 seconds before entire computer locks.

Did a fresh install of Win 8.1 Pro 64 bit on a different drive . Just used the nvidia driver from ms (no physx) for now . I can stream video now (so far) without lockups and hard powerdown. I'll stress it longer tomorrow with more videos . MS is already trying to upgrade me to 10  , no thanks .

Well I decided to try the nvidia driver from nvidia (355.82) with only physx . Driver was working fine for about 2 days until I started getting the full screen freeze ups and driver recovery blues . Driver will reset 4 times in under a minute ! Uninstalled it , used the nvidia driver from MS , back to no issues . Something with the nvidia drivers do not get along with the motherboard or just with Adobe Flash player .

Oh, GPU. I had .98 installed. I just came back from 4 restarts in less 15 minutes. Trying your method.
 

Using generic drivers. Crashes are significantly less, but still occurring.
 
If I was getting 4 crashes an hour, I might be getting one every two hours.