I Have purchased HP 15Boo2TX laptop with Windows 8 pre installed. As the performance was sluggish i downgraded the same to windows 7. deleting all backup files and HDD. Now i want to get windows 8(as i want to upgrade the same to windows 10). I downloaded an windows 8 iso and tried to install it but it says that the key is not matching with this version of windows. Kindly help.