How to replace the main Windows boot drive in your PC

Samsung 960 EVO
Samsung 960 EVO (Image credit: Windows Central)

Things break and slow down over time in PCs. Likewise, every year newer, faster, stronger parts come to market. That doesn't just apply to desktop PCs, either, and even in today's world of slim, light Ultrabooks, there are still parts that can be replaced.

Consider the case of your main Windows boot drive. It's integral to using your PC, and if it fails you're in a predicament. Whether this is why you need to replace it or you just want something better, the process is the same. And it's fairly straightforward.

A replacement drive

960 Evo

If you have a PC that supports Non-Volatile Memory Express (NVMe) drives, our recommendation goes to the Samsung 960 Evo (opens in new tab). It's not Samsung's absolute fastest consumer drive, but the price difference (around $60 on the 500GB models) to the 960 Pro, coupled with a not-massive performance gap, gets it the nod.

It's available in 250GB, 500GB and 1TB sizes, starting at a very reasonable $125 for the 250GB version.

See at Amazon (opens in new tab)

Of course, not all PCs will be able to accept these super-fast drives. If your current PC is only using a mechanical hard-disk drive (HDD) and it's here that your Windows install lives, it's a great time to make the upgrade to a solid-state drive (SSD). A 2.5-inch drive will fit in place of any 3.5-inch HDD (though you may need an adapter) and it's much faster. The Samsung 860 Evo (opens in new tab) is a great choice at $150 for 500GB.

WD Blue

If you're looking for a great m.2 SSD that isn't NVMe, a 500GB Western Digital Blue (opens in new tab) is a great option at $130.

If you have multiple drives in your PC, you can get away with a smaller boot drive, but I wouldn't recommend anything smaller than 250GB. If it's your only drive, get the biggest you can afford. But always go SSD if you can for your Windows boot drive. You won't regret it.

More: How to use the BIOS or UEFI to check if your boot drive has failed

Removing the old drive and installing the new one

Samsung SSD

The exact process here will vary depending on what sort of PC you're using. A desktop tower will be very different than a laptop, for example, which will be different than a small-form-factor PC. The basic steps are mostly the same, but the location of the drives will be different, and what you have to remove from your PC to get to the drive will also vary.

It's a good idea to have a basic toolkit (opens in new tab) handy and a magnetic tray (opens in new tab) if you have one because the screws in a PC really are tiny.

The guide linked below is specific to an HP Omen laptop, but it shows you step by step how you'll be removing and installing the different types of drive you're likely to be dealing with.

How to upgrade the HP Omen 15

Reinstalling Windows 10

Windows 10

Perhaps the most daunting part of this process is reinstalling Windows 10, but it's still not that bad. The important thing is that you can get hold of an image for the OS, and the easiest way to do this is to download it using a PC. If your main drive failed and you don't have another PC, however silly it sounds, ask someone for help. All you need is a PC and an internet connection.

The process involves downloading the image file from Microsoft and creating a USB drive that you can use to boot your PC and install the OS. The easiest way to do this is to use the Microsoft Media Creation Tool, linked in the guide below.

How to install Windows 10 from USB


To boot your PC from the USB stick, open up your BIOS or UEFI when you first turn it on (a press of something like F2 or F12 may be how to access it) and set your boot priority to USB drive as number one, then your new main drive as number two. It's a good idea to remember to change it back, though, once you've installed Windows, otherwise if you leave a USB drive connected to your PC and it'll try to boot from this. As soon as your Windows install is complete, remove the USB stick, too, or it might just reboot into the installer.

Installing Windows from the USB drive is very straightforward and the on-screen prompts will walk you through every stage. You don't have to worry about license codes anymore if you already had Windows installed, they will be automatically attached.

For more on doing a clean install of Windows 10 check out the guide below.

Ultimate Guide: How to do a clean installation of Windows 10

That's all there is to it. If you have any other tips or tricks be sure to share them in the comments.

Richard Devine is an Editor at Windows Central. A former Project Manager and long-term tech addict, he joined Mobile Nations in 2011 and has been found on Android Central and iMore as well as Windows Central. Currently you'll find him covering all manner of PC hardware and gaming, and you can follow him on Twitter and Instagram.

  • How to keep our previous Windows 10 PRO License? I've upgraded from Windows 8.1
    Moreover can we keep our existing Windows 10 PRO OS and system files even when changing the HDD?
  • Your Windows 10 Pro license is based on your device, not your HDD. There are no files on the drive that record your license and activation. Those are based on the unique hardware IDs of the device and stored in the Microsoft Cloud. If you clone the old HDD to the new storage device the OS and all your apps and files are on the clone.
  • Just to further clarify this, the cloud license is based on an aggregate of hardware IDs in your system -- including, but not limited to, your CPU, network card(s) and hard drive.  Hard drive IDs are established during formatting and cloning will typically duplicate that ID. So a cloned system will boot up already activated since Windows doesn't actually look at the hard drive serial number -- only the partition ID (serial number) written to the drive. If, however, you perform a clean install without cloning, your hard drive will have a new ID which will usually require your Windows OS to be reactivate. Since only a single one of the aggregate IDs has changed (the hard drive), most times Windows will reactivate automatically with no trouble. But there are occasions -- particularly if you upgrade other parts or if you upgrade frequently.
  • The new drive that beats both Samsung 960 Evo and 960 Pro is Intel Optane 800P... It's not cheap now because it's new, but sure beats Samsung in 4k random read and write which is the indicative of everyday i/o performance. Note that the higher sequential read/write is not the criteria for drive performance!
  • NO. Just no. If your main drive works fine, CLONE IT. The ONLY reason to reinstall Windows is if your current installation is having problems that can't be fixed any other way. All SSDs come with or qualify for cloning software. And USB interfaces for m.2 and msata drives exist so it's easy to copy the boot drive and simply replace it.  If and only if after trying this one has problems should one then perform a clean installation. I really wish people would stop spreading this outdated thinking that fresh installations are always better.
  • I agree. It is a belief from XP days when Microsoft used file copy instead of sector copy methods.
  • The only problem is that you may have relics of old software installation...
    I take a personal case : my old laptop was running Windows 8 and was upgraded to Windows 10 Pro. With the exact same files and software installations, I needed 120Gb to store everything. On my Surface Pro 4, I was only at 70Gb.
    After a complete year and a half, 3 major Windows updates and some upgrades for softwares, I use now 90Gb. So, fresh installation may help to have less storage used, no ?
  • If you uninstall old software those "relics" usually have very little impact -- and the time you save (and in some cases, the data that is not lost unexpectedly) is more than worth it. This article makes it sound like reinstalling Windows is a breeze. But those of us who have actually had to do it for clients know that all it takes is a network card that requires a driver to make a "simple" process a pain -- especially if you don't have another computer that can perform the download. And that's not even mentioning the things non-technical people miss when trying to replicate their previous installation. As for saved space, make sure to run disk cleanup in admin mode and have it perform the Windows Update Cleanup (as well as the rest of the options). And don't trust software, Windows, or even disk cleanup to kill temp files. Find them and delete them yourself. Yes, you'll save some space with a clean installation, but a properly maintained system where you routinely run cleanup and uninstall things you don't need will not differ greatly from a clean installation.  
  • Yes but even with Disk Clean Up in admin mode, dfrgui.exe to TRIM the SSD, CCleaner and manually erasing and AppData folder, there was still a huge gap of storage between those 2 devices... I install a lot of computers for clients (I'm currently studying in the IT security & network and work as student in the company of my father while also as Brand Ambassador for Microsoft) and I confirm my problem is the exact same for everyone so... In fact, it's impossible without a fresh installation, to be able to delete all relics of old softwares and old updates not more in use as they're in many subfolders of the computer. It's like recent updates for Windows 10 who corrected BSOD on older architecture (Intel 1st to 3rd gen) while creating on newer ones (Intel 6th gen) before receiving an other update which nearly erased BSOD from my computers. Still, I have once or two a month BSOD on my SP4 for a bad memory allocation on startup (mainly).
  • I won't touch CCleaner and remove it whenever I see it -- but that's another debate. There are also other things to clean if you dig. And if you're hoping Defrag will TRIM your SSD in Windows 10, you're mistaken. "Huge" is subjective. And again, I said these "relics" seldom have any actual effects. Often they are just extra files that nothing accesses. They take up space, but do not affect performance. As for your BSOD -- have you installed symbols and downloading the applicable analysis tools to evaluate the dump file? Citing a bi-monthly BSOD out of context isn't particularly useful here. Finally, while I don't typically engage in "measuring" contests (been doing this too long to care what people think), I will say I've been optimizing computer since before MEMMAKER started to automate it for us. So take my advice or not -- your mileage may vary. :)
  • Forjo, can you clarify some things for me? (I used to clone drives but had specialized hardware device that was pretty cheap.) First, what do you mean by a USB interface on an M.2 drive? I haven't seen that on any M.2 drives I've seen, do you mean an adapter that will plug into it to make it USB? And (2) what cloning software do you use?
  • Amazon has lots of USB to M.2 cables, chassis' and adapters. For software, I've typically just use what comes with the drive -- Samsung uses Clonix, Western Digital uses Acronis Trueimage. I also have a copy of Trueimage that isn't tied to a specific SSD brand. I've had a few instances where drives wouldn't clone due to an inability to resize partitions. Using the event logs and some research you can identify unmovable files to resolve those issues. But if all efforts to clone fail, you can always use Windows to backup and restore -- again, assuming the source partition is less than or equal to the size of the new drive. In only one instance have I been forced to perform clean installations -- a Dell AiO that would not boot following cloning or even backup and restore. I couldn't even perform a clean install until I switched back to BIOS mode. I can only guess that there was something in the UEFI BIOS that didn't support the Samsung EVO.
  • What's better : clone the drive or fresh install Windows ?
    Also, when changing completely of desktop computer (but still being in a similar architecture, just a more recent one) : install the drive of the old computer and run Windows as usual or reinstall Windows ?
  • Better depends on the condition of the installation. If things are working, just clone. If you have any problems later that you can't fix otherwise, only then should you consider a reinstall. Also, ever since Windows 8 Microsoft has changed the boot-up hardware sequence. Where before Windows would crash if the disk controller driver failed to load, now Windows will trigger a hardware detection during bootup. The end result is that most Windows 8 and 10 installation are completely hardware portable. You can drop them into another computer effortlessly as long as they have the same BIOS (BIOS vs UEFI). And there is even a relatively easy to perform process for upgrading from BIOS to UEFI without reinstalling if you want UEFI later (though I don't think you can go the other way). Bottom line, DO NOT REINSTALL unless you have problems dictating that you do. And even if you plan to, CLONE FIRST. Keep your old installation as a backup in case you miss something and don't realize it until later. And, as always, backup your computer before trying any of this.
  • I would fresh install if i do not have any data on the boot drive and have spare time to install all the apps and programs. Otherwise clone.
    For component upgrade such as motherboard, you have to fresh install the OS since the old drive only has the driver signatures of the old components and the PC won't boot!
  • People who have apps and programs and NO DATA are extremely rare. A lot is stored or synced to the cloud these days, but not everything.  Reinstalls lose things like favorites, e-mail, saved games, preferences, calibrations, and other application data that most people don't even think about until later when they try to use the reinstalled software and find that it lacks their customizations and settings. As for component upgrade -- not correct. Windows 8 and Windows 10 will redetect hardware when placed into another system. As long as you don't go from BIOS to UEFI or UEFI to BIOS you don't have to reinstall -- only reactivate.
  • Not entirely true. I moved a Windows 10 drive from an old intel X38 board to an AMD 990X board. The pc started up, Windows did a 'getting devices ready' and within 5 minutes I was back at the desktop like nothing had happened
  • Thanks for that confirmation, Brian -- I hadn't had the opportunity to try going between processor architectures. I suspected it would work, but had not tested it.
  • Thanks for your advice. So, even if I leave the Intel/Nvidia architecture, I could still start my Windows drive and be able to use it ? 🙂
  • Good Luck with that!
  • Try it. Perform an image backup first, but you have very little to lose. According to Brian, it'll work. And, anecdotally, I can offer the evidence of going from a physical machine to a virtual one with a different processor and back also working. The installation in my son's PC went from an ATOM micro PC, to a Dell Lattitude i7 1st gen to his current i3 7th gen. And it's completely trouble free.
  • I am thinking of doing this but I really and I mean really do not want to have to do a clean install and start from scratch. I have a lot of certain programs, apps, games and drivers that would take me weeks to get back.. Is this really possible?