Disable Driver Signing in Windows 7 Using Group Policy Editor::
Disable Driver Signing in Windows 7 Using Group Policy Editor
If you want to turn off device driver signing in Windows 7 completely, do the following.
1). Hit the Win+R keys together to open the run dialog.
2). Type gpedit.msc in the run edit to open the local groups policy editor.

3). Expand ‘Administrative Templates’ (it’s under ‘User Configuration’).
4). Expand ‘System’.
5). Click ‘Driver Installation’.

6). In the right panel, double click on ‘Code Signing for Device Drivers’.
7). Choose ‘Enabled’ in the window that appears.
8). In the options area, choose ‘Ignore’.

9). Click 'Apply' button then click 'OK'.
10). Restart your computer.
This disables drivers signing in Windows 7, and now you can install and run unsigned drivers in Windows 7.