What was the system requirements for unity 5.1.1

I just wanted to know the system requirements of unity 5.1.1

I have windows Vista and wanted to get unity 5.4.3 but it said that it wasn’t supported but I wanted to see if 5.1.1 was supported

Likely the same as they are now. They haven’t really changed much and Unity tries their best to cater to lower-end devices.