CAn i use a recovery cd to install Operating system on a new Hard drive?

[tulsantide12]

I bought a HP laptop last year and my hard rive is dead .Luckily i back up everything on my external hard drive but my question is I can buy a new hard drive but what about teh operating system taht came with my laptop do i have to buy operating system Vistam home in my case do i haev to buy again ?