????
Please don't do that.
Uninstall your current drivers, plug in the 1070 THEN install drivers, doing so with the previous card in the system has the potential to stuff with settings.
You MUST uninstall the GPU driver before installing the new one even if it is the same make of GPU. Example Nvidia to Nvida. The only time you do not is if you are replacing the GPU with the same exact model GPU. example 970 to a 970.
Certain Parts of the driver that is installed will not be needed but other parts for the new GPU will need to be added. Other than this nothing else should be need to be done to swap the GPU over.
You MUST uninstall the GPU driver before installing the new one even if it is the same make of GPU. Example Nvidia to Nvida. The only time you do not is if you are replacing the GPU with the same exact model GPU. example 970 to a 970.
Certain Parts of the driver that is installed will not be needed but other parts for the new GPU will need to be added. Other than this nothing else should be need to be done to swap the GPU over.
In addition to Chugalug's link you should also run Ccleaner or any other registry cleaner before reinstalling the driver. This will help prevent any overlapping issues with drivers. Basically it will give you a clean slate for the driver to start from.