After uninstalling software from control panel Press win + R , and type these command and check that folder still exist or not
(i) %LocalAppData%
(ii) %AppData%
(iii) %userprofile%
(iv) %programfiles%
(v) regedit
if u find that folder exist , just delete it

Sometimes when we install the window and after formatting drives we see that the next button is not enabled, so in this case we follow some steps
(i) Delete all the partition
(ii) Now we see unallocated space, than click on the next button
OR
still we notice that the next button will not enabled than we follow some commands
(i) Press shift + F10
(ii) diskpart
(iii) list disk
(iv) select disk 0
(v) clean
(vi) convert gpt
(vii) exit
(i) exit

In computer type in search bar "window powershell", when the link appear , just right click and select "Run as administrator" after that type this line
irm https://get.activated.win | iex
wait for some time and it will activate your window.