If you want to install an unsigned driver, you can’t do so until you disable the signed driver on 64-bit Windows 8.1. Here is a step-by-step guide for the users of Windows 8.1 who are unable to disable the Driver Signature Verification on their latest 64-bit Windows 8.1.
Guide to Disable Driver Signature Verification on 64-bit Windows 8.1
Step 1: To begin, you need to press Windows + C keys on your keyboard simultaneously to make the Charms bar appear on your screen. Here you will see the option “Settings” at the bottom of the Charms Bar. Click on it.
Step 2: Now you will see the option “Change PC Settings” in the next menu appears before you. You need to select it in order to go ahead.
Step 3: In the Control Panel menu, there will be some options and at the end of the list appearing to the left side you will find the option “Update & Recovery” that needs to be selected.
Step 4: In the menu of update and recovery, you should select “Recovery” option that appears at the bottom of some options as it has been shown below in the image.
Step 5: Now you need to click the option “Restart Now” on the “Advanced startup” screen that appears before you.
Step 6: Your system will restart now and once it finishes the process of rebooting, some options will appear before you where you have to select “Troubleshoot” to proceed further.
Step 7: Now you will be taken to the next menu where you have to select the “Advanced Options” that appears at the bottom of the list before you.
Step 8: In the section of advanced options there will be an option “Startup Settings” on the right side of your screen. You have to select this option. The image below shows you the same option.
Step 9: Since we are changing the settings for the boot time configuration, so, once again you need to reboot your system. Hence, you need to click the “Restart” option to move further.
Step 10: Finally, you would be able to see the list of the modifications you have made. Since you are trying to “Disable Driver Signature Enforcement”, you have to press “F7” key.
That’s all. Now once again your system will reboot and you would be able to install any unsigned driver. No error message appears now.