So I had this computer given to me by a friend.. its a gigabyte z68 motherboard, 2600k processor and im making gaming upgrades to it... However, the old 500 gig hard drive is starting to fail... sector errors..... I have a newer 1tb HDD in another PC but barely used....... What should I do? Flash the 1TB HDD and install it into the computer with the failing HD? keep in mind windows 10 is on the failing HDD and I dont have a key for it.... Im lost :/