best way to do clean install with 2 NVMe drives, multiple partitions

I know the best practice advice is to detach all drive except the target install drive. I have 2 issues with that advice, for when I upgrade my desktop. (My laptop is already on Win 11).

My desktop system's NVMe drive has C, E, and F partitions. I'm planning to install a second NVMe drive (to replace a slow HDD).
Issue 1: My NVMe drive has C, E, and F partitions.
Issue 2: I'm planning to install a second NVMe drive (to replace a slow HDD). (To replace a cruft-ridden Win 10 Pro install).

So what's the best way to proceed?

You have to delete all partitions and clean install windows on unallocated space. See step 10 here.

I guess I'm finding it hard to believe you have to nuke all your partitions to do the install. Although I haven't done it with Win11, I did this tons of time with Win10. In a quick Internet search, I also see many references to installing with existing partitions.

That being said, I would SURE have backups of any data, and I would remove any additional physical drives.

You do not need to nuke all partitions! Give me a couple min and I'll put together an explanation.

Please standby...

x509 said:

Issue 2: I'm planning to install a second NVMe drive (to replace a slow HDD). (To replace a cruft-ridden Win 10 Pro install).

Click to expand...

I take it from this statement that you want to clean-install Windows 10 to a new NVMe?

I've found it best to
1. remove all drives except the one intended for the Operating System [Main/Boot/System].
2. let Windows clean/wipe the drive as it desires, less problems later. Let Windows create partitions as it desires, may be 3 or 5 total, some quite small and usually not normally accessible..
If having 2 drives the OS can spread parts of itself across both and be broken if one is removed. Same if the BIOS is set for enabling RAID or AHCI RAID.

Okay, sorry for the delay. Had to deal with something.

Let me start with the easy answers first:

1) Additional data partitions will remain intact so that is really a non-issue. I still always suggest having a backup in case something totally unexpected happens due to hardware problem, bug, etc.

2) It would be simplest if you install the 2nd NVMe drive AFTER you install Windows.

Now, the long-winded stuff.

Lets start under the assumption that you only have a single drive in the system. It has your Windows partition, the other partitions that Windows creates (EFI, MSR, and Recovery partitions) and maybe a couple extra data partitions. I believe that this is what you said your current state is.

Optional: Before doing a fresh install of Windows, I would suggest changing the label of your Windows partition to something like "Windows" or anything that you will remember while you still have your existing Windows running.

Now, boot from your Windows installation media. Proceed in the installation to the point where you need to pick a partition to install to. If you labeled your Windows drive "Windows" then you should clearly see that "Windows" label. If you do not, you should be able to pick out the correct partition by the size .

Note that in the image below I don't have additional data partitions as you do. That won't make any difference.



Windows will gladly reuse the other Windows partitions noted earlier. As for other data partitions, those will be left alone.

IMPORTANT: If you have other drives in the system, especially if they were added AFTER Windows was installed, you can have different behavior. In your configuration, this is not an issue.

Once Windows installed, then go ahead and add the 2nd drive.

Nuke it! Just Nuke it! Muah-ha-ha-ha! Of course you'll have to save all your important files and what not on another drive first. Make sure all other drives are disconnected once you do and only the drive with Win 10 on it having that legal license key is still connected. After this connect a freshly formatted "new" drive for a Win 11 install. Then have at it. Once you have your Win 11 installed go to the activation section and run the link for finding a license key. It will find your old, messed up Win 10 and ask to use that key. Agree to the deed and let Win 11 steal the key from your Win 10. After this, you're in the clear. You can nuke that puppy and format it and turn it into a Windows backup drive.

Of course things change. For all I know Win 11 doesn't rob old operating systems of activation keys anymore. That would really be too bad if it didn't. You could just buy a new key. You could also just keep both operating systems and run dual boot. The options are endless. Still, nuking old janky operating systems is so much fun. Me, I'd already be firing up my flame thrower. User preference prevails.

Hmmm...maybe he stepped out for lunch.

IMO the whole purpose of a clean install is to create everything new and clean. I want no old junk left hanging around when it comes to my OS partitions. Taking shortcuts and doing workarounds are fine for some things. But knowing my partition scheme and and the data on those partitions is what and where it is supposed to be is not one of them. It's easy enough to image any extra partitions one has created. Then after a clean install is done, reduce the C: partition, create whatever extra partitions you want and restore the image. But that's just me. I make every attempt to not half-do anything just to save a little time.

Scott said:

Hmmm...maybe he stepped out for lunch.

Click to expand...

I hope I didn't scare him off. On a more serious note the only reason I would do what I suggested is because the idea of having a bunch of useless partitions taking up space on my main drive seems pointless. If the other drive wasn't already messed up I'd probably opt for a dual boot. It really depends what the user wants to use the PC for. To each their own, right?

I think Scannerman has the answer. It's personal preference. Truthfully, I can't imagine significant issues keeping the data partitions and doing a clean install on the existing Windows partition. I'm guessing that since he has the drive partitioned that way, he probably intends to operate that way.

I have a 2TB NVNe drive for my system drive, and it also has a bunch of other partitions. If I were to install Windows clean again, I'd just plop it into the existing space that Windows now has. Yes, I would backup all the other partitions, I do that anyway regularly. Of course, both my main and secondary system have a second 2TB NVMe drive, so the backups are pretty speedy, a total image of my data drive takes only a couple of minutes, same for the work drive. My other two drives are mostly archived files, and they don't change that much, so a differential backup of those is also lighting quick.

I would, however, open up and unplug the other two drives on the system to make sure the Windows install didn't get confused.

You MUST disconnect only the boot able drives. I always mention All drives for security reasons (so you don't delete the wrong partition during installation).
If you don't disconnect all boot able drives it will install the OS on the target drive and the boot manager on the other boot able drive.

It isn't clear to me if you want to reinstall win 11 on the drive that has C:, E: and F or if you want to install Win 10 on another NVMe that will replace the HDD.

- If you intent to reinstall win 11 on current NVMe drive, you need to detach the Win 10 drive ( remove the SATA or PS cable from the HDD) and you only need to delete the EFI, MRS, C: and Recovery partition. You DON'T need to delete the E and F partition. Point to install on the unallocated space created when you deleted EFI, MRS, C: and Recovery partition.
- If you're installing Win 10 on the other NVMe that will replace the HDD, you need to remove the NVMe drive that has C:, E: and F and detach the Win 10 drive ( remove the SATA or PS cable from the HDD). Delete ALL partitions on the target drive and then proceed.

To install as UEFI - GPT, you MUST boot the Win 10 or Win 11 installation drive as UEFI, NOT Legacy

For a better advice, please post a whole window Disk Manager image of ALL your drives. Don't forget to expand the columns so we can read them. How to Post a Screenshot of Disk Management
If you have a MiniTool or AOMEI Partition use it instead or Windows disk manager.

Scott said:

I take it from this statement that you want to clean-install Windows 10 to a new NVMe?

Click to expand...

Not necessarily. In fact probably not. My new NVMe is 2 TB vs 1 TB for my older drive.

glasskuter said:

IMO the whole purpose of a clean install is to create everything new and clean. I want no old junk left hanging around when it comes to my OS partitions. Taking shortcuts and doing workarounds are fine for some things. But knowing my partition scheme and and the data on those partitions is what and where it is supposed to be is not one of them. It's easy enough to image any extra partitions one has created. Then after a clean install is done, reduce the C: partition, create whatever extra partitions you want and restore the image. But that's just me. I make every attempt to not half-do anything just to save a little time.

Click to expand...

The E and F partitions do not need to be deleted. They do need to delete the other partitions and let the installer create the needed partitions.