I'm thinking of upgrading the HHD in my Mid-2010 15" MacBook Pro, (currently running 10.6.8). I'm also considering doing a fresh install of Mavericks on this new drive, and trying out Parallels and VMWare Fusion (never used them before). If the software (or Mavericks) don't meet my needs, I just wanna keep the setup I've currently got, and not upgrade the drive. So... could I prepare the new drive externally with Mavericks/Parallels? (by putting it in a USB enclosure)? I'd like to try booting from it as an external USB, running it for a bit to see if I like it. This means I won't have the hassle of touching my current setup. If I do like the new setup, could I then just literally take the Mavericks drive out of the USB enclosure and put it into the Macbook as the main drive?? The reason I ask is in case OSX installs different files depending on if the drive is in a laptop or desktop, or in the above proposal neither (coz it'll be an external drive at time of installation).