Installing a second hard drive in your Laptop is pretty easy if you don't really use your optical drive. Swap it out with a Hard drive caddy. But save that cd or dvd drive. You can still use it. I show how at the end of this vid.
Laptop shown is a Dell Inspiron 15 3567
After your install, If you Hard drive doesn’t show up try this:
Right click the windows icon in lower left corner of task bar
Select Disc Management
your second disk will show, but not active(initialized)
need to make active by right clicking on window that represents the drive
then make active partition(drive)
select to create partition (if applicable)
select format (if applicable)
wait and drive will change status to "healthy" at top windows and your drive/data will now be accessible and visible in 'My Computer'
Amazon links:
Universal Hard Drive Caddy amzn.to/2GO8lnx
Hard drive I used amzn.to/2IhrQHv
External USB 3.0 enclosure for optical drive amzn.to/2GOIOKP