please help me

[sai_4_]

I am using hp notebook with windows 8.1
Later i upgraded to windows 10 it was very slow and cant get back to 8.1 after 1 month
Then i installed windows 8.1 from my friend
I worked fine for a month then again upgraded to 10
Due to my fate again came back to 8.1 then internet was not working so again i kept windows 8.1 cd and installed then it was very nice for first use the i turned off after restarting it was saying startup error and i did many attempts to turn on but it wasn't always saying startup error please read my problem and help me please
Thanks in advance

 

[basroil]

1) Make an installer USB using the instructions at http://windows.microsoft.com/en-us/windows-8/create-reset-refresh-media
2) Download the drivers from your manufacturer and extract them to the USB flash drive
3) Plug in the USB stick to the laptop and restart. Select a re-intall option
4) When a "load drivers" text appears in the bottom left, load the "storage controller" drivers and "wireless network" drivers
5) Continue with install and follow the instructions
6) After you make a new account, remove the USB stick

it should work after that.