You buy a new SSD (or HDD), install it as the primary disk in your system (desktop or laptop -- check laptop specs as not all laptops contain a second hard drive bay) - [the new disk is] known as
disk 0; install Windows onto the new SSD/HDD; then are left with the old Windows installation on the secondary (or old) SSD/HDD (known as
disk 1).
What do you do with it (the old drive/ the information/data on the old drive - now called the
secondary disk) considering that you would like to use the 100+ GB of storage space that the old Windows installation is taking up?
i.e., you want to remove the old Windows installation from the secondary drive (the old disk).
First off, if you do purchase a new SSD/HDD and plan to install Windows onto it, do not install the secondary drive yet (the old Windows boot drive) until
after the installation of Windows is done on the new disk.
I recommend this so that Windows does not place any boot data/files onto the now second, old disk during Windows installation. If you have both disks installed during a new Windows installation and the old disk fails and needs to be replaced, you could be left with a real mess on your hands that could involve having to reinstall Windows again, thus losing all of your installed programs and other important folders and files that you need and/or want.
If there are files on the now old SSD/HDD disk that you want to keep, the easiest way is to copy such folders and files to an external USB drive or USB stick (or just make sure not to delete them until they have been copied to your new Windows installation disk after Windows installation). If you go the external USB route - Just make sure that the USB device is large enough to hold all of the files that you want saved. External USB drives and sticks are relatively cheap today, even compared to the same sized USB storage device of just 2-3 years ago.
Once that you have copied all of the folders and files over to the USB device that you want saved or if you decide that there is nothing from the old drive that you want to save, you can use Windows Disk Management (
diskmgmt.msc -
Create and format a hard disk partition) to format the drive (erase/delete ALL files - and create a single partition so that the old disk is then ready to accept new files written to it from your USB backup(s)) or use a 3rd party app like
KillDisk -
How to erase hard drive by Active@ KillDisk? Disk Eraser, Disk Wiper, Disk Format & Disk Sanitizer., which will perform a low-level format on the drive deleting every folder and file on the secondary drive by writing
0s and
1s over every byte of the old disk. It often performs this procedure several times to assure that the data on the disk is in fact not readable ever again - or recoverable.
After you have installed Windows onto your new SSD/HDD, plug the old drive back in (desktop computer) or install it in the secondary hard drive bay on your laptop. Go into Windows Disk Management (
diskmgmt.msc) and assign a drive letter to it -
-
Change a drive letter
-
Assigning a Drive Letter to a Volume - Win32 apps
If the now-secondary drive/basic volume is too large and you want to create two or more smaller drives from it, use Windows' Disk Management's disk shrink utility -
Shrink a basic volume
It is very easy to use and the documentation in the above link is very helpful. Be sure of your calculations, i.e., the number of drives and sizes of each that you want to end up with because reversing shrinking is much more difficult than shrinking the original disk is and in some cases does not always work.
For info, I have a 1 TB HDD that I shrank into two (2) 500 GB drives, assigning the letters
a: and
b: to them so that they appear first on a regular Windows/Files Explorer screen. I like having the two (2) smaller drives as it makes it easier for me to locate folders and files.
The other options that you have to remove an old Windows installation from a secondary disk is to install the drive after installing Windows and then delete unnecessary folders and files from it.
You can do this three (3) basic ways -
1. Windows/File Explorer
2. CMD Prompt Screen using folder and file deletion commands
3. A 3rd party app like Tree-Size Free -
TreeSize Free | JAM Software
Starting with a basic listing of directories (folders) located in the root of the newly created secondary drive can help immensely as there are directories that have no personal files in them so you can start by deleting these immediately.
If using Windows/File Explorer, hold down the left SHIFT key while clicking on the folder or file that you wish to delete. You want to use this method because it bypasses the Recycle Bin and therefore permanently deletes the folder or file in question. Typically when you delete a folder or file, Windows simply moved it into the Recycle Bin in case you change your mind and want to restore it. You can use this method if you want to, but I find it easier and faster to just delete the files permanently. It is your call.
Here is a directory listing of my current c: drive, which will become a different drive letter at some point soon (as so far described in this tutorial) because this HP laptop is running Windows 8.1 x64 and I have purchased a new 1 TB SSD and plan to install Windows 10 x64 on to the SSD, then move the 1 TB HDD to the secondary drive bay (again - as so far described in this tutorial).