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Windows 7: Win 7 HomePrem 64-bit, 32-Bit and Pro 64-Bit; Multiboot Drive Letters

04 Mar 2012   #1
Bart B

Windows 7 Pro 64-bit w/Virt. XP, 7 Home Prem 64-Bit, 7 Home Prem 32-Bit
Win 7 HomePrem 64-bit, 32-Bit and Pro 64-Bit; Multiboot Drive Letters

Here's my problem after installing other Win OS's on my PC.

First, original hard drive has Win. 7 HomePrem 64-bit on drive C.

Second, added a partition (drive B) to the original hard drive then installing Win. 7 Pro in it. Then installed Virtual XP on top of Win. 7 Pro.

Third, added a second 250 GB hard drive (E) then installed Win. 7 HomePrem 32-bit on it.

Installed EasyBCD 2.1.2 to manage multiboot issues. But the hard drive letters don't stay the same. And it takes a long time to go from starting Windows to complete desktop with all OS's.

What's an easy way to assign letters to hard drives such that they stay with them so whatever OS I use, the physical drive's letters showing on Disk Management and Windows Explorer stay the same?

After "freezing" drive's letters, what problems may arise?

Thanks in advance,


My System SpecsSystem Spec
04 Mar 2012   #2


Please post back a screenshot of your maximized Disk Management drive map with listings, using Snipping Tool in Start Menu. Tell us what is on each partition.

If you incorrectly installed WIn7 from an OS instead of booting the installer, it takes away its ability to always be seen as C when booted.
My System SpecsSystem Spec
07 Mar 2012   #3
Bart B

Windows 7 Pro 64-bit w/Virt. XP, 7 Home Prem 64-Bit, 7 Home Prem 32-Bit

Attached are screen shots of each OS's disk management.


Attached Thumbnails
Win 7 HomePrem 64-bit, 32-Bit and Pro 64-Bit; Multiboot Drive Letters-win-7-hm-prem-64-bit-dsk-mgt.jpg   Win 7 HomePrem 64-bit, 32-Bit and Pro 64-Bit; Multiboot Drive Letters-win-7-pro-64-bit-dsk-mgmt.jpg   Win 7 HomePrem 64-bit, 32-Bit and Pro 64-Bit; Multiboot Drive Letters-win-7-hm-prem-32-bit-dsk-mgmt.jpg  
My System SpecsSystem Spec

07 Mar 2012   #4

Windows 7 Ultimate SP1 64-Bit

1. I see you have given Win 7 Pro 64-bit drive letter B. Drive letters A and B are reserved for floppy drives and shouldn't be used for a system partition.

2. Whichever operating system you boot into will automatically take drive letter C with the others taking the next available drive letters, which means you can't freeze the drive letters as you put it.

3. I also notice that the 100MB System Reserved partition has been given drive letter J. This partition shouldn't have a drive letter from a security point of view. The system reserved partition contains the boot files and if the drive letter changes it could make the computer unbootable. When you boot into the other operating systems drive letters will change as I explained so you need to remove drive letter J.
My System SpecsSystem Spec
07 Mar 2012   #5


In the second screenshot OP is booted (Boot label) into Pro 64 showing as B, which means it was incorrectly installed from another OS instead of booting the installer or it would show as C when booted.

I would clean reinstall Pro to that partition by correctly booting the installer which should autoconfigure the Multi-boot correctly since the other two OS's appear correct.

If not, install Easy BCD, on Edit OS Menu tab delete all other listings and then Add the other two OS's back by Name, Type, letting the app autodetect the drive letter.

You can also boot the single OS HD when needed by tapping the one-time BIOS Boot Menu key which will keep it independent.
My System SpecsSystem Spec
07 Mar 2012   #6
Bart B

Windows 7 Pro 64-bit w/Virt. XP, 7 Home Prem 64-Bit, 7 Home Prem 32-Bit

Thanks for both replys.

About the drive letter B; does anyone on this forum have the clout to convince Microsoft to change their Windows software so when one wants to change a drive letter, "A" nor "B" does not show up on the available drive letters available? If these letters are not good to use for hard drives, something should prevent users like me from doing so. I'll change it and see what happens.

I installed Win. 7 Pro 64 from a Microsoft DVD with its activation code. To reinstall Pro to that partition (after relettering it) by correctly booting the installer, how do I "boot the installer?" I'm not familiar with this process.

EasyBCD is installed and I used it to set up the OS selection startup screen. I may well do as suggested to let this app detect/use the OS's drive letters. Might be the easiest to do without reinstalling Win. 7 Pro then Virtual XP Pro on top of it.

And I'll remove the drive letter from drive J; didn't know about the security issue. But I'll need a bit of help on this one as I see no way to remove the drive letter; only change it. How do I remove the drive letter

Thanks again for the help.

All OS's now boot in reasonable time. Something changed regarding this; have no idea what. The backup drive wasn't showing up after booting Win 7 HP 32-bit, but I let it crunch away after opening "Computer" to see all the drives. A popup window appeared saying drivers got installed for it, then it finally appeared.

Things are looking better, best regards to all,

My System SpecsSystem Spec
07 Mar 2012   #7


Here's how to remove the System Reserved drive letter:
Drive Letter - Add, Change, or Remove in Windows 7 - Windows 7 Forums

You can run Win7 on B if you want. It might not present problems but if it does you have the reinstall option, however you can never change the letter of an installed OS without ruining it.
How to Boot your Computer from a Bootable CD or DVD

Is your Triple boot working now? You can adjust Menu defaults and timer at Control Panel>System>Advanced>Startup.
My System SpecsSystem Spec
07 Mar 2012   #8

Windows 7 Ultimate x64 SP1

Have you considered simplifying with virtualization? I can't imagine ever having a need or want to have the same OS installed several times on the same system.
My System SpecsSystem Spec

 Win 7 HomePrem 64-bit, 32-Bit and Pro 64-Bit; Multiboot Drive Letters

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