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Windows 7: Change boot disk / reassign C: drive?!

07 Feb 2014   #11

Windows 7 Professional 64bit

OK... so I've been offline most of the day today... but I ultimately got it worked out on my own... I was impatient last night so I messed around a bit on my own... I'd basically figured out what WHS said, "the installer always grabs the first primary active partition it can find." Since I couldn't find a way on my own to prioritize the new drive... I did the following to fix the problem:

1. I used the Windows Repair Disk to get a command prompt without running an OS on any HD.
2. Using DISKPART in DOS - I deleted both partitions on my old drive to make it all unallocated space.
3. I tried to boot again hoping that it would boot to the new drive, but something in the boot record was messed up.
4. I used the Windows Repair Disk again to auto detect and repair my windows installation.
5. It then booted correctly using the System Reserved and assigning C: to the new drive alone.
6. I then used Disk Management to reformat the old drive... and that FINALLY assigned the volume a higher drive letter!

So now "the first primary active partition it can find" is the new drive (as it should be)
...and the old drive is entirely re-formatted as a single volume that can function as a backup (as it should be)!

And all is well in the valley. :)

This might not have been the quickest way to make it happen, but I learned quite a bit as I became quite well acquainted with DISKPART and in the end it all worked out!

My System SpecsSystem Spec
07 Feb 2014   #12
Microsoft MVP

Windows 7 Ult. x64

Good outcome
My System SpecsSystem Spec
07 Feb 2014   #13
Microsoft MVP


Would you please post back a screenshot of Disk Management - Post a Screen Capture Image so we can look it over to see if it's correct?

Just for the record: Win7 cannot change its booting drive letter once installed under any circumstances. It will always see itself as C when booted unless it is incorrectly installed from another OS which blocks it from using C. This is why it should always be installed from boot, with all other HD's unplugged so that the boot files are not placed on the first-in-order Primary partition.
My System SpecsSystem Spec

07 Feb 2014   #14

Windows 7 Professional 64bit

Gregrocker - I did read your post, but I didn't happen to see yours until AFTER I'd already begun messing with things myself... so it just happened to come to late for me to follow your suggestions.

Also, if I was reading your note properly it sounded like your suggestion was actually targeted for restoring the System Reserve and C: to what was labelled as "Disk1" (Did I read your notes right? Or did I misunderstand?)... but what I actually wanted was the reverse... I wanted to re-format "Disk1" and instead get it to boot entirely on "Disk0"... So the System Reserve in use was already on the correct drive and it was the C: that was being assigned to the wrong drive.

Anyways... I'm actually out of town for the weekend (hence my being impatient and anxious to get it fixed before I left)... but if you all are still interested to review the final result then I can post a capture of the Disk Management when I get back on Sunday evening.

In any case, I'm grateful to this community for helping me resolve it... Even though I didn't use the suggested methods in this thread, it was other threads from this forum that sparked in me the idea of using DISKPART and helped me figure out how to accomplish the task in DOS.

My System SpecsSystem Spec
07 Feb 2014   #15

Windows 7 Ultimate 64 bit SP1 x64

Randomly Disk 1 becomes Disk 0 and vice versa if connected via SATA.

That is one of the stupid race hazards that Microsoft make us live with.

I find the drive numbers tend to be allocated in one sequence on a cold start from power-down and no disks rotating
and a different sequence after a warm Reboot with disks still spinning.

I learned the hard way to ensure that every volume has a unique system volume name.

If you every need to use a Linux BOOT rescue CD you will discover it will NOT show you drive letters C:\ and F:\
My System SpecsSystem Spec

 Change boot disk / reassign C: drive?!

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