So my hdd on the laptop has completely failed on me and i need to buy a new hdd. The question i have is can i buy a win 7 64 oem and use the liscence key that is under the laptop to activate it so i can save the one it comes with cause i will be building a computer soon and would like to use the code it comes with for my new comp if possible. If it would work would both be working simultaneously? And how would i install