Mark wants to know if it's safe to use Kaspersky antivirus software. Leo says that Kaspersky is a great AVS utility, but it has fallen under a cloud of concern because the Russians may have used the software as a spying tool. The US Gov't has banned the use of it as a result. So it's probably best to err on the side of caution and avoid it.
If you need an AVS, Leo recommends using Windows Defender. It's free and comes with Windows 10.