The problem is that many devices' USB drivers are unsigned drivers. Digitally signed drivers are signed using code signing certificates. This certificate is an electronic fingerprint that indicates which company the driver was produced by as well as an indication as to whether the driver has been modified since the company released it.
To install the USB drivers for the Nextbook7 (NX700QC16G) on windows 8 and up, you need to disable "Driver Signature Enforcement".
Steps To Disable Driver Signature Enforcement
Press the Win + C keyboard combination to bring up the Charms Bar, then click on the gear with the word "Settings".Click on "Change PC settings".
Click on “Update & recovery”.
Then click on the "Recovery" on the left hand side.
Once selected, you will see an advanced startup section appear on the right hand side. Click on the “Restart now” button.
Once your Computer has rebooted you will need to click the "Troubleshoot" option.
Then click "Advanced options".
Then click "Startup Settings".
Since we are modifying boot time configuration settings, you will need to restart your Computer one last time. Click "Restart" button.
After the PC restarts, you will be given a list of startup settings that you can change. The one we are looking for is “Disable driver signature enforcement”. To choose the setting, you will need to press the F7 key.
Your PC will then reboot and you will be able to install unsigned drivers without any error message.
Download the USB Drivers
Unzip the file. It should create a folder called win_7_8_usb_drivers. Remember this and where it's at because you will need to browser to it later.
Right click on "My Computer" and then choose "Manage". This will open the "Computer Management" window.
In the panel on the left, click on "Device Manager".
In the panel on the right, find your PC's name (usually at the top of the list). Right click your PC's name and choose "Add legacy hardware".
The "Add Hardware Wizard" should start up. Click the "Next" button.
Click the option "Install the hardware that I manually select from a list (Advanced)".
Click "Show All Devices" at the top of the list. And click the "Next" button.
Click the "Have Disk" button.
Click the "Browse" button.
Browse to win_7_8_usb_drivers
If you have Windows 7 or 8 32bit select the usb2er_Win7.inf file.
Or if you have Windows 7 or 8 64bit select usb2er_Win64.inf file.
Or if you have Windows 7 or 8 64bit select usb2er_Win64.inf file.
Click the "Open" button.
Click Next on the wizard to install the drivers. When promoted for security issue just click on install any anyway to finish the driver installation.
Click Finish
Restart your PC.
