Tinywindows 7

Tiny7 x86 Rev. 01 is a Windows 7 installation of 700 mb. The creator ‘Experience’ has removed many items from the installation that are not necessary for home use. This results in a super fast Windows environment. With this installation even an old Pentium 4 laptop or desktop will be fast enough for home use!

https://blackeyez007.blogspot.co.il/2015/09/windows-7-tiny-unattended-fully.html

tiny7

https://www.reddit.com/r/windows/comments/3juffo/tiny7_running_with_only_884_mb_of_ram_id_never/

http://www.clonemysdcard.com/en/windows-tiny7-installeren-van-usb-stick/