There is a problem with the 770M in windows - I have an Alienware M17x R4 with a GTX 770M installed with Bios A13 (not unlocked) and it works fine. The problem with installing the driver is that you need to manually edit the inf file to introduce your device into the inf - for some reason Nvidia say this 770M model that I have (11E0) is not officially supported or something.
So the process is basically like this:
1 Extract the video driver to its own folder (it's probably already extracted to C:\Nvidia\etc\etc if you've already tried to install it.
2 Navigate into the Display.Driver folder and open nvdispi.inf with notepad (or any text editor).
3 At the bottom of the inf file you'll find a big list of cards and their device numbers and you just need to rename one of them (Use a similar card like a 970M) and replace the name and also the 4digit code for that card - BUT take note of the original 4 digit code.
4 Once you've renamed the card to Nvidia Geforce GTX 770M then you also need to rename all the similar references to the old card to the new card.
5 Reboot the machine into unsigned driver mode (in win 8 and 10 it's a quirky and awkward process, I force legacy mode on these newer OSs as I prefer being able to press F8 which is a much simpler solution (damn you M$!)
6 Once booted in unsigned mode you can install the new driver no problem and then after that annoying process you can continue as normal.
So in my example:
NVIDIA_DEV.139B = "NVIDIA GeForce GTX 960M"
NVIDIA_DEV.11E0 = "NVIDIA GeForce GTX 770M"
I rename the DEV.XXXX 4 digits, and also the 960M to 770M then I "REPLACE ALL" the 139B to 11E0 in the file.
My card has an ID of 11E0 but yours may not - you can use GPUz to see what your 4-digit code would have to be.
This is a better method that using LaptopVideo2Go for me because those drivers never seemed to allow me to alter the screen brightness once the driver had started (only at the Bios screen). If this method seems too confusing or too much effort - I urge you to try the LaptopVideo2Go drivers at least to get started and make sure your new card is working okay. Then later you can explore making a modified inf.
I hope this is helpful