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Windows 7: Change drive letter for presumable needed boot disk

05 Dec 2009   #1

Windows 7 prof
Change drive letter for presumable needed boot disk

Windows 7, 32 bit, 12 partitions on 3 hdd's, Windows 7 on C:

When migrating to Windows 7 I first tried to update my Vista which I had used happily for 2 years. Installation went fine, but there were too many problems after.

So I bought a new 1 GB hdd and installed Windows 7 there from scratch. It is on a partition with drive letter C.

I copied most of my old partitions to the new hdd, went fine.

When trying to delete one of the old hdd's with EASEUS Partition Master Home 4.1.1 manager software, there is one partition on it (which once before was called C, then successfully renamed to Z ) which I can't delete. I has on it the following folders:
System Volume Information (locked)
-->and files:

They are only 30,5 MB in size. So I resized the partition to 1 GB.
EASEUS characterizes it as Status = System, Pri/Log = Primary. Windows Disc manager characterizes it as System, Active, Primary Partition.

My question is: Can I change the drive letter from Z to B without risking the whole system to be unbootable? (and maybe never be bootable again?)
When trying I just get the usual Windows warning.

I would be most grateful for an answer explaning what and why or why not.


My System SpecsSystem Spec
05 Dec 2009   #2

Vista Ult 64 bit Seven Ult RTM x64

Hello Mick,

Welcome to 7 Forums.

Could you post a pic of Disk management. Info here if needed. A Preferred Method of Uploading/Posting Screen Shots

My System SpecsSystem Spec
05 Dec 2009   #3

Vista U32 , now Win7 64

timmendorf.. first download a wimpe disk or create one.

have it on a dvd or flash disk ready to boot (first test it boots)...

if so, then yes, you can start playing around... change it to b from z just a drive letter should be fine yup.

If system becomes unbootable.. its NOT permanent at all, just needs some manual typing to fix (from the aforementioned wimpe disk).. worst case scenario would be to move the bootmanager manually to your new C , then u cud delte that partition + have the boot active system in right place. but anyway, id recommend my scripts for that but I dont think im releasing them as open source after all, as I got no feedback at all from this forum members, which I would of appreciated.

Ayway, as long as you have that wimpe disk, and it fails I guess I can help you as long as u have internet to come and ask again n explain what went wrong.


actually nvm...

but hint: boot with wimpe , then go to your new C ,

I build a 'mikepe' with my program I wrote (which has bootrec.exe as well),

so i run bootrec /mbr (so i guess forget this option)
( i think it will work without this anyway.. if not OOPS.. you can make a wimre from your installation, again my program SUCK does this all for me )

run from \windows\boot
bootsect /nt60 all /force

go to old C (Z:)

attrib -s -h
del *.* and/or format it.

your wimpe disk is X:
copy files from X: as explained in this file i give you

build the bcd on your new C:

off you go.

Attached Files
File Type: txt building a bcd.txt (1.6 KB, 65 views)
My System SpecsSystem Spec

05 Dec 2009   #4

Windows 7 prof

Thanks, Gary,
here you are.


Attached Thumbnails
Change drive letter for presumable needed boot disk-comp_man1.jpg  
My System SpecsSystem Spec
05 Dec 2009   #5

Windows 7 prof

@ Solar
Thanks to you too.
Whats is a "wimpe disk"? Do I have to buy any programs from Symantec to create one?
My System SpecsSystem Spec
05 Dec 2009   #6
Microsoft MVP


That Z: partition won't delete because it's active system partition holding the MBR for Win7.

You should have unplugged other drives before reinstalling Win7

First, mark C active in Disk Management.

Now unplug DISK0 so MBR can be recovered into C where it belongs. Either plug C: HD into that cable or set it as first HD to boot (after DVD) in BIOS.

Now boot into the WIn7 DVD and run Startup Repair 3 separate times as it has multiple issues to fix including rewriting the MBR to C.

Now you can plug Z: HD back in but may need to use free Partition Wizard CD to delete Z. Boot into Partition Wizard, right click Z, delete. You may also need PW to set C active earlier.
My System SpecsSystem Spec
05 Dec 2009   #7

Vista U32 , now Win7 64

no lol. You could buy my program and be eternally happy for 12 bucks or so... but come back for that when you get another boot problem one day kiddo (don't think it iwll be releasable for another month as Iam converting from open source scripts to native binaries)

let's see, just push f8 , and get into the recovery environment, then get to the command prompt, from then non you can do the instructions I said, but try it the other way first; to a person with light knowledge of the boot procedure, it feels more secure than typing out things manually... sigh sometimes I miss the days of dos :)
My System SpecsSystem Spec
06 Dec 2009   #8

Windows 7 prof

Thanks a lot guys.
I'll try and come back.

My System SpecsSystem Spec
06 Dec 2009   #9

Windows 7 prof

Well, guys, I'm back.
@gregrocker: Thank you very much. It worked perfectly. I got rid of the useless little partition.

My System SpecsSystem Spec
06 Dec 2009   #10
Microsoft MVP


Great news, Mick.

Can I ask how many times you had to run Startup Repair to re-write the MBR?

Did Z: HD delete/format after replugging with Disk Management, or PW?
My System SpecsSystem Spec

 Change drive letter for presumable needed boot disk

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