Before fitting the new 1070 card.
Any model of graphics card you had fitted in your system before hand should of had the video card driver removed before the old card was removed from the system and swapped for the 1070 card Mick.
If the card was either another Nvidia based card off a different model number.
Or a ATI based graphics card prior to the installation of the GTX 1070 card.
You always have to perform this task to avoid situations where the game will fail to run after an installation of a new graphics card.
As a driver conflict is the cause.
Older pc games also require a patch or a fix when a DX 12 hardware enabled card is fitted to your system.
It is due to the fact that no direct X 12 cards existed when the game tittle was made and the game is looking for a direct x 11 listed hardware device.