It is c/w Windows 10. It is much better to do clean install of Windows 10 than upgrade from windows 7 to 10.
I'm not sure if my Optiplex 3020 (specs below) is compatible with Win10 - does anyone know, or have experienced going from W7 to W10 on this model? Dell Optiplex 3020 Mini Tower, Intel quad core i5-4460S 2.9 GHz. 64GB SSD, W7 Home SP1, 500GB 3.5 HDD for all non-system stuff, optical drive, 8GB ram.Thanks for any advice, Kind regards, Niloc1017  
Optiplex 3020 - Win7 to Win10 upgrade possible?