Windows 10: Drive letter designations after Dual Boot install

Hi, I've installed W10 in my laptop in a dual boot configuration with W7 successfully. I used this tutorial https://www.tenforums.com/tutorials/2...ndows-8-a.html I'm setting up to do the same thing in my desktop and have a couple questions about drive letter designation after doing it. I created a 30G partition on the C drive of my desktop for the W10 install.

My laptop has one drive, the OS "C" drive, I created a another partition for W10, after installing W10 using the USB ISO "boot from USB" instruction when I'm in W10 it shows as the C drive, and the W7 partition is inactive D drive. Just the opposite when I'm in W7, it shows as the active C partition and W10 is the inactive D partition.

On my desktop I have the 120G C drive for W7, a 500G D drive for backups, a fixed CD-ROM E drive, and a virtual CD-ROM F drive. I've made a 30G partition on the C drive to install W10 on for the dual boot. The question is when the auto backup runs (I have it backup & image every Sunday at 7:00pm) it backs up the C drive to the D drive. Will the W10 dual boot install change my backup drive letter to something other than D, or will the non OS physical drives keep the same drive letter? I will have to remember to be in W7 for it to be the C drive when it backs up, but my concern was if the dual boot was going to change my backup drive to something other than D. That would affect the backup.

I've attached disk mgmt. below, FYI the G drive is the USB with the W10 ISO

Attachment 21744

:)

 

Dual boot Windows 10

There are other considerations when dual booting with Windows 10 (8.1 or 8) as well. Turn off Fast Startup in both Windows 10 installations to prevent file or drive corruption after cold booting from one OS into the other. Warm reboots are not affected.
System Restore points may also be messed up/deleted if you're not careful in configuring restore settings on the hard drives.

The boot drive is identified as C: in the currently booted Win10 but the drive with the other installation appears as a different drive letter which you can change to whatever you want using Disk Management. You can rename each OS installation in the bootloader
to identify them individually.

To effectively hide either OS install from the other, instead of using NoDrives you can remove the drive letter of the "other" Windows boot drive (in Disk Management) in each of the Windows installations. That drive or partition will still show up in Disk
Management without a drive letter but the drive will not be displayed in File Explorer or, AFAIK, any other software.

 

Designating drive letters in Windows 10

I have four 1Tb Sata drives, set up as two mirrored RAID arrays. On both arrays, each drive set is partitioned with a Primary for the OS, and 5 extended partitions for different storage purposes. On the first array, I have Win 7 Ultimate (32) installed
on the primary, with extended partitions labeled D, E, F, G, and H. On the second array, I had Win 7 Ultimate (64), installed on the primary partition, with 5 extended partitions. The system is set up as a dual boot, with Windows boot manager, installed
on the 1st array, controlling the boot process. The 1st array, with Win 7-32, has been my day-to-day system. And, my plan is to transition to the 2nd array with the 64 bit system, and eventually use it as my day-to-day system.

I just finished upgrading the second array with Windows 7 Ultimate (64) to Windows 10. And when finished, the process has changed the drive lettering from what it originally was. When I boot to the Windows 10 OS on the 2nd array, it sees the primary partition,
on the 2nd array as drive C, which I expected, but it has designated drives D, E, F, G, and H as the extended partitions on the 1st array instead of using the partitions on the 2nd array as it did when it was Win 7-64. And it now has designated the extended
partitions on the 2nd array as N, M, O, P, and Q. I want the Windows 10 install to see the extended partitions on the 2nd array as drives D, E, F, G, and H, and not extended partitions on the 1st array.

If I change the drive letters in the Windows 10 install, on the 2nd array, to D, E, F, G, and H, and change the drive letters on the 1st array to other letters that will not conflict, will this affect how the drives are seen when I boot to the Win 7 OS on
the 1st array?

 

I installed W10 on the 30G partition I created on my C drive, while in W10 it shows as the C, W7 shows as D, backup drive shows as F.

Booted into W7, C is W7, D is the backup drive, F is the W10 install, so my question was answered.

Summary: While booted into W7 the C and D drives are the same as they were before W10 dual boot install. While booted into W10, W10 becomes the C drive, W7 is D and the backup is F. Fixed CD-ROM drive E didn't change, virtual CD-ROM is now G

Disk management below while booted into W7, F is W10.

Attachment 21783