Help me pleae

question is do I need anti virus on both OS or having AV in only one will work?

I have purchased several SSD drives that I am cloning to match hardware I am upgrading. I am using a USB 3.0 Drive enclosure that recognizes standard SATA drives but not the SSD. When I attach the same enclosure on a Windows 7 machine it sees the drive right away and assigns it a drive letter...