Add 2nd HDD for storage w/o deleting Windows partition?

My current PC has Windows 10 Home (OEM license, activated). I just inherited a faster machine with Windows 10 Pro (OEM license, activated). I want to take my Home HDD and stick it in the Pro machine as a 2nd drive. But I want to keep the Windows Home partition because inevitably there will be something on it I want or need.

I will NOT attempt to boot from it -- I think I can exclude it in BIOS and/or manually select the Pro drive as needed. I just want access.

Question is, will the Windows Pro installation balk at the mere presence of the other Windows setup on the separate drive? or worse, do something to disable/erase it?

I thought of hiding that partition before (and after if needed) installing but that defeats the purpose. Also prefer to install internally rather than use an external enclosure.

Hoping that's clear and sufficient, TIA for your help!

steve108 said:

Hello JL and welcome to tenforums ,

Here’s an idea. Backup and Restore with Macrium Reflect

Install it on the new PC and make a MR Rescue USB. Then boot the old PC from USB and make a full backup of the boot drive and save it to an external USB.

Now you can take the external USB and connect it to your new PC and from MR browse the backup image C: partition. MR will mount the partition as a new drive letter which you can then use File Explorer to look/browse at and feel comfortable you have access to all your files.

Once you are comfortable with this, you can format the drive from the other PC and use it entirely for extra storage.

Also long as you keep the backup image, you can always use it to restore backup to the old drive or a new SSD and make your old PC usable again.

Thanks, but I'm familiar with image backups and use them all the time with Acronis TI. More importantly I do NOT want to remove the Windows Home installation from the older/second drive. That's the main concern: I want to leave it in place. I can HIDE it if need be and explore/extract files from an existing ISO but that's time consuming. So what I really want is to know is if the booting Windows Pro on HD0 will leave the non-booting Windows Home on HD1 alone and treat it like any other part of the disk, with any location accessible on demand. THX

You won't have any problems other than having to have administrator access in order to access the data files on the old HDD.

THX everyone ~ HDD with Win Home partition intact is installed as second non-bootable drive and all is well!

That said, the one thing I forgot is that if I need anything from the Home user registry I'm in trouble -- info on loading remote hives is weirdly complicated and scary -- so of course in the back of my mind is the following notion should it ever be necessary:

1) pull system offline
2) manually boot into Home installation
3) ignore any What's Going On? errors from the OS
3) grab what's needed from registry
4) restart, reconnect and boot normally from Pro drive

Famous last words, but I'm known for that on my block

spunk said:

You shouldn't really need anything from the Windows Registry on a secondary non booting drive.
If you know exactly what you are looking for in the Registry, you can access it via the Command Prompt.
First Changing to the drive letter of the drive and then following these instructions How to Edit the Windows Registry from the Command Prompt

Thanks but that's a bit too command-line-y for me. The things I need are probably limited to application settings which some older apps don't store in INI files but their reg folders -- I spent so much time getting things just so on the previous installation that trying to recreate all settings without INI files to copy/paste is a major PITA. It also means I don't necessarily know "exactly" what I'm looking for.

I'm afraid that would incorrect. The Apps and Programs on the second hard drive would be using the active registry that Windows loaded - not the dormant old registry on the second hard drive. In addition the Apps and Programs on the second hard drive would expect to find everything installed with them, such as DLL files, on C: drive, and they second hard drive where those files were installed to is no longer C: drive.