I had the same problem and I was able to fix it. (All tho I'm having FPS issues which I didn't have on W8)
What I did was remove the Config folder found in My Documents/My Games/Hawken.
I replaced it with the default Config folder found in your hawken install folder(steam/common/Hawken/.., not sure about full path, on my phone).
I also turned on Compatibility mode (W8) & run as Admin on the Hawken executable found in the Win32 folder in your hawken install location.
Not entirely sure if that was all I tried, but I think those are the things that actually fixed it for me.
As I mentioned above, I do have some FPS issues, it drops to 20-30FPS sometimes in larger servers which it didn't on W8. I've got intel i5 quad running at 4.4Ghz, 32GB RAM and 780Ti, I used to get 60FPS solid all time (vsynced) when I was on 8.
Using nvidia's latest beta driver for W10
Hope you get it up and running!
If not, there's a thread that covers startup issues. You can find it in the Pinned post in this section of the forum.
EDIT
It's not in this section of the forums, my bad. This topic should be moved to the Med Bay.
Anyway, you can find it in the Med Bay section ;)
Edited by TGrave, 20 May 2015 - 03:38 PM.