Using an Old Boot Drive as a Storage Drive in Your New PC

Why May I Need this Article?

It's not uncommon for folks to look at the hardware in their old system and want to use it in their new system; you spent good money on that hardware, so of course you want to take advantage of it! The problem is, specifically regarding old Windows boot drives, adding an old drive to a new system can create instability.

Here are some things that can happen when installing an old Windows boot drive in a new Windows system:

What do I need to do to prepare?

Before installing the old drive into your new system, we recommend purchasing and using a USB drive enclosure to connect it: this is a device that lets you use an internal SATA drive like you would an external USB drive. While it's possible to get through this by simply booting to your new drive and formatting the old one, the errors listed above can happen even if you only boot this way once! In addition, Windows will make an attempt to protect internal SATA drives that detect Windows created boot partitions to prohibit users from accidently deleting important Windows operating system files. There are other options, too, like using a SATA PCIe card or enabling SATA hot-swapping, but this way results in little unnecessary hardware and it makes the process very simple. For these reasons and more, it's highly recommended you use a USB drive enclosure.

One last recommendation is to disconnect all of your extra drives. While it's not necessary and there are steps in place to guarantee you're not erasing the wrong drive, the safest way to avoid accidentally erasing the data on a different secondary or tertiary drive is to simply unplug either the data or power cable from the extra drives. You can't accidentally erase a drive the computer doesn't see!

Drive enclosure

Vantec NexStar-3 External 2.5-inch Hard Drive Enclosure

This will format your old drive!

Formatting your old drive

Now that we're ready, let's go ahead and boot up your computer with the drive disconnected. Once you're in Windows, right-click on your Start menu and select either "Windows Powershell (Admin)" or "Windows Command Prompt (Admin)". This process is the same for both of those shells. but for clarity I'll simply refer to it as 'Powershell'.

Now, in Powershell type in the following command and press 'enter':


Doing so should take a moment to load, before listing your computer's name and a new command line starting with 'DISKPART>'

loading diskpart

Next, type in the following command and press 'enter':

list disk

This will show you all of the drives currently installed in your system. Now, plug in your USB drive enclosure, go back to powershell and run 'list disk' once more. The reason for this is now you can clearly see which of the listed drives is the new one by comparing the two lists. In the example below, you can see that the drive I added was listed as Disk 6:

list of drives in system


The next step is to select the appropriate drive. The syntax looks like the following, but replacing the # character with the actual number of the drive we're trying to wipe:

select disk #

Now that the drive is selected, all there is to do is to clean it.


If you're certain it's the correct drive, type in the following command and press 'enter'.


You'll know it worked because it will say "DiskPart succeeded in cleaning the disk."

Powershell after cleaning the drive

Once it's done, you're ready to install the drive into your computer! You can choose to format the drive now, or after installing it into the chassis as a SATA drive. One thing to consider, though, is depending on the age of the drive, you may be better served using it as an external drive. To reiterate, having an older/failing drive installed in your computer can cause serious performance issues, and using it as an external drive makes it easier to test as it nears the end of its days.

Partitioning your drive

Regardless of whether you choose to use it as an external or internal drive, you've still got to partition it. For a guide on partitioning this drive, check out our article, here.

You'll know the drive was partitioned properly by checking it's listing in Disk Management. If the drive shows a volume, with a name and drive letter, you've succeeded! If you get through this and the drive still doesn't appear in File Explorer, go back into Disk Management and make sure it's got a letter assigned; closing Disk Management too early can result in the drive letter not getting assigned.

If that happens, simply right-click on the drive and choose "Change Drive Letter and Paths…" and it will bring you to a Window showing the assigned drive letter and paths. From here, select 'Add…', pick the desired drive letter, and then click OK on both Windows.


Hopefully this helped with safely formatting an old OS drive and installing it into your new Windows system. If you are a Puget Systems customer and are in need of further assistance, feel free to reach out to our support team with your order number and we'll be happy to help you!

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