Should I upgrade my laptop(Lenovo Z40) to Windows 10?

[Abrar_3]

My laptop is lenovo z40 specs: Core i5 processor 1.3Ghz~2.6Ghz
4 Gb DDR3 RAM
1TB HDD
Currently running on Windows 8.1
GPU is Nvidea 820M
So should I upgrade my laptop to Windows 10?

 

[popatim]

too late now, its not longer free...
Plus I wouldn't anyways, win10 runs a little slower then Win8 to me.