Mouse and keyboard don't work on windows 7 after install windows 10

[S4ng]

Hi. First of all sorry for my not perfect English. As i wrote my keyboard and mouse don't work after i have installed windows 10 Pro Insider Preview. I tried to run windows 7 in safe mode but it still doesn't work. I read that disabling Driver Signature Enforcement may help, but I can't even go to the advanced boot options because my F8 key doesn't work. I'm out of ideas. Keyboard and mouse are USB connected. I hope you can help me.

 

[Jazmac]

Are you dual booting your computer?

 

[S4ng]

Hi. Problem solved, I formated Windows ^^