Viruses can move from strain 7 to strain 10.
Viruses can move from strain 7 to strain 10.
Likely unless you instruct it to erase the drive and start over.
If you skip using Windows 10's refresh feature post-upgrade, most programs should stay functional. The kernel changes minimally from Windows 7, so those apps have a solid chance to work. It's unclear if the refresh process also clears the registry, leaving hooks behind. In short: yes, it's likely you'll still have them running. Still, try the refresh if you prefer not to start from scratch. As always: fresh install – best option.
Many suggest using Malwarebytes because of its effectiveness.