Restart your Windows 7 machine and as the computer starts press F8. The startup screen should look like this:

Select the Disable Driver Signature Enforcement option and click Enter.
After rebooting, install the MOD Driver.
If Windows 8 or 8.1 (Win 10)
1. Open the Charms Bar in Windows 8 and select “Settings”:

2. Select “Change PC Settings”:

3. Select “General”: ( or "Update & recovery")

4. Scroll to the bottom of the General page and select “Restart Now” under “Advanced Start-Up”:

5. Once the PC comes back up, select “Troubleshoot”:

6. Select “Advanced Options”:

7. Select “Start-Up Settings”:

8. Select the Restart button:

9. Press either the F7 key or the number 7 key from your computer keyboard.
This disables the Driver Signature Enforcement, which will allow you to install a modded driver. After pressing either key, your computer will reboot:

After rebooting, install the MOD Driver.
*source: http://www.fotoclubinc.com/blog/how-...-on-windows-8/