Upgrade hard drive and instal new OS on 2008 24" iMac
I would like to upgrade my 320GB hard drive with a new 3TB hard drive.
At the moment i have 4 gig of RAM.
from other answers here I think I need to use the same brand hard drive, mine is a WD.
I'am thinking of buying a WD black 3TB drive. Will this be ok or do i need to buy the blue or green ?? heating problems etc ??
I have watched the help video here on ifixit on how to physically change my hard drive and feel confident to do so.
My question for this issue is how to instal the operating system etc to be able to restart my computer with new hard drive. Can I change a blank drive into my computer then reinstall OS or do I a need boot drive etc or install something on the drive before installing? I have found some answers but all a bit unclear for my head.
Also on this older computer with a bigger hard drive what is the best OS to install? The original system was snow leapard. I have also found info that installing Yosemite will not be good for my older system but have been running much later software until I have had hard drive issues.
Any help with these questions will be greatly appreciated - Ben