Depends on the CPU. The cutoff for Windows 10 support is the old Pentium D and Pentium H/T chips. They lack the necessary instructions sets to run anything beyond Windows 8.0, 8.1 will also fail to install.
i have windows 10 running on 1st gen core i3 and i5 CPU's. for your security it would be best to go with windows 10. an SSD for either version of windows is a great option though.
Depends on the CPU. The cutoff for Windows 10 support is the old Pentium D and Pentium H/T chips. They lack the necessary instructions sets to run anything beyond Windows 8.0, 8.1 will also fail to install.