Do I need to activate Windows 8 if I used it before?
I already used it before, do i need to buy Windows 8 again, if i get the official ISO file from the Windows website?
The Windows installation environment will automatically detect your Windows 8 OEM license which is stored on the ACPI table on your laptop's motherboard. Since finding a Windows 8 ISO is difficult, I would suggest just using the Microsoft Windows and Office ISO Download Tool by HeliDoc.net.
After you have the tool installed and the ISO downloaded create the installation disk and install Windows 8.