1. If it is a Win8 (primary) dual system, when selecting the system, select the bottom: change the default value or select other options-> Select other options-> Troubleshooting-> Advanced options-> Windows startup settings—Restart, and then select Disable driver forced signing.

2. If it is not Win8 dual system (main) or Win8 single system, press Win+C-> after entering the system; Bring up the charm menu-> Change computer settings-> Settings-> General->; Restart the advanced startup immediately-> Troubleshooting-> Advanced options-> Startup settings-> Restart, and then disable driver forced signing.