how-to-remove.usは安全ですか？

This site is fake. On their website, one of their removal tool stated, "Connect all your external data sources to your PC (Usb keys, external drives …)" That question the legitimacy of the site. You never ask a customer to connect your external device. This is an attempt to infect as much as they can and to spread their viruses through the fake and infected removal tool. What's funny is that even a false positive is listed as a virus on their site for removal. Do not trust this site. Otherwise, go ahead and get your PC infected by them. If you really want to clean your PC, use reputable program and go to the official site such as BitDefender or Kaspersky.