The first thing to do after installing a hard drive is to partition it. You have to partition a hard drive, and then format it, before you can use it to store data.
To partition a hard drive in Windows means to separate a part of it and make that part available to the operating system. Most of the time, the “part” of the hard drive is all usable space, but it is also possible to create multiple partitions on a hard drive.
Do not worry if this sounds like more than you thought – partitioning a hard drive into Windows is not difficult and usually only takes a few minutes to do.
How To Partition a Hard Drive in Windows
Note: Manual partitioning (as well as formatting) on a hard drive is not necessary if your ultimate goal is to install Windows on the drive. Both processes are included as part of the installation procedure, which means that it is not necessary to prepare the unit yourself. See How to Clean Install Windows for more help.