Try
Removal instructions for DNS Unlocker
Remove “Ads by DNS Unlocker” virus (Uninstall Guide)
Remove DNS Unlocker version 1.4 Ads (Virus Removal Guide)
In case none of the above guides help/work for you: All of the above-mentioned Removal Guide sites offer free expert help.
And/or, you might want to think about resetting your Windows 10:
Recovery options in Windows 10
Everything You Need to Know About Refreshing and Resetting Your Windows 8 or 10 PC
How to Use the Windows 10 Reset Your PC Feature
Good luck with everything...