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Windows 7: Changing boot drive letter ?

09 Nov 2010   #1

win 7 pro x64
Changing boot drive letter ?

Hi all,new here to the forums i have a question reguarding my boot drive leter.
recently bought a ssd installed my edition of win7pro 64 onto it
no problems except i had my old hdd still plugged in which was my c drive letter ,thus i installed operating system onto my ssd with an e drive letter.ok so i have tried to run a couple of programmes which i use which have failed because the programme is looking for a specific file in c boot directory which i obviously havent got....hope you can understand what im getting big question how do i change my ssd boot drive letter to :c and that all my existing programmes will still work.
many thanks for any help

My System SpecsSystem Spec
10 Nov 2010   #2

W7 Professional x64

programs that you have installed onto the drive after the OS that need to call files other than the EXE to work will not know where to look for them, and likely have to be re-installed.
My System SpecsSystem Spec
10 Nov 2010   #3
Microsoft MVP


If you had booted the Win7 installation DVD instead of run it from your old Win7, it would have made whichever OS you were booted into at the time the C Drive, and kept C on your SSD when you wiped or unplugged your HD.
My System SpecsSystem Spec

10 Nov 2010   #4
Bare Foot Kid
Microsoft MVP

W 7 64-bit Ultimate

Hello jmboy, welcome to Seven Forums!

The only real way to sort this is to disconnect all but the SSD from the motherboard and do a clean install, have a look at the info below and be sure to post back with any further questions you may have and to keep us informed.
information   Information

After you have made backups of everything you care to save and you want to do a real wipe "clean all" to the Hard Disk Drive (HDD) have a look at this tutorial at the link below, it over-writes everything, all the old Windows code including all the old Windows drivers, giving you the best possible space to install Windows 7 to; it goes hand-in-hand with a clean install.

SSD / HDD : Optimize for Windows Reinstallation

How to Do a Clean Installation with Windows 7

My System SpecsSystem Spec
10 Nov 2010   #5

Windows 7 professional x86/

Yep - it's impossible to reassign C:
My System SpecsSystem Spec
10 Nov 2010   #6

Windows 7 Home Premium x64


Partition Magic comes with a utility called Drive Mapper that does what you want.
I've only used it a couple times and that was quite a while ago.
It's pretty straight-forward but you must be very careful to "Read The Screen"!
It can really mess things up if you don't take your time to do it right- one step at a time.
It will do exactly what you tell it to do- blindly.
You can get Partition magic at Softpedia.

Before using this tool, I'd make backups like crazy...
My System SpecsSystem Spec
10 Nov 2010   #7
Bare Foot Kid
Microsoft MVP

W 7 64-bit Ultimate

Partition Magic is obsolete for use with Windows 7 and may destroy the partition structure.
My System SpecsSystem Spec
10 Nov 2010   #8
Microsoft MVP


There is no way to reliably change an OS drive letter once its assigned. It will almost always brick your OS.

Win7 will always install itself to C, or see itself as C in a Dual Boot, unless you run its installer from the other OS. It needs to be booted except in the case of an in-place Upgrade.

Only if the OS letter gets changed during reimaging causing it not to start, Paragon Rescue boot CD has a utility that can change it back.
My System SpecsSystem Spec
10 Nov 2010   #9

win 7 pro x64

thanks to all for replies, i think im gonna have to bite the bullet and reinstall...once again thank you for your input.
My System SpecsSystem Spec
10 Nov 2010   #10
Microsoft MVP


Here are some tips to get a perfect reinstall, so you can then save an image so you never have to reinstall again:

The installer is mostly driver-complete, with newer arriving quickly via optional Windows Updates. Any drivers then missing in Device Manager can be found on the Support Downloads webpage for your model computer or device.

Install updates and then programs slowly over time to gauge performance after each. Don't let any programs write themselves into msconfig>Startup as they become freeloaders on your RAM/CPU and can spy on you. I only allow AV and gadgets.

Use a lightweight free AV like MS Security Essentials which works perfectly with Windows 7 Firewall.

When it is finished, clean and order the HD perfectly using state-of-the-art free CCleaner then Auslogics Disk and Registry defraggers monthly. CCleaner - Free software downloads and software reviews - CNET
Auslogics Disk Defrag - Reviews and free Auslogics Disk Defrag downloads at
Auslogics Registry Defrag - Free software downloads and software reviews - CNET

Then save a Win7 Backup image externally so you never have to reinstall again, just reimage the HD or replacement using DVD or Repair CD. Backup Complete Computer - Create an Image Backup
My System SpecsSystem Spec

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