Windows Repair 4.0 Changed Drive letters so PC won't boot [SOLVED]

[eLaReF]

Since upgrading to Win10 from Win7 I have always had odd 'permissions' problems, possibly from running Win7 as Admin, which Win10 doesn't like, so now run as a user with Admin rights.
Decided to use Windows Repair to sort out permissions.
Just before the end of running Windows repair, I saw some text in red but wasn't quick enough to read what it said

Machine is a 16Gb Win10x64 Home edition desktop - Latest Slow Insider Preview version but can't remember which

PC doesn't boot after BIOS screen
Having used a Win10 Installation disk, I'm in, in DOS mode and find the drive letters have been changed:-
C was E
E was Z
G was SYSTEM
J was DVD
X was Boot
Quite happy changing drive letters from Windows, but if I ever knew how to do it in DOS, I've long forgotten
Not sure I could rename Drive C anyway?
I could obviously re-install Win10 from scratch, but am assuming it would use the current HDD C instead of the SSD now G. I also have far too much installed that I don't really want a fresh install, although it would cure my permissions issues

Is there a CMD line to reallocate drive letters?
Would it work on C?

thks

[Boggin]

I'm not sure how that has happened and you are right in that Windows will not allow you to assign a drive to C:

This could have been a result of running a Beta version of Win 10.

I'll pass this on but as you have an install disk, can boot up with it to navigate to the Command Prompt and enter rstrui.exe

That will get you to your restore points which may get you back to where you were.

I don't think the cmds bootrec /rebuildbcd or bootrec /fixmbr would work in this instance.

Did you run all of the default checked repairs, include any more or just the ones for the Permissions ?

Are you saying you have been running the machine with the hidden admin account activated ?

[eLaReF]

Win7 m/c used Admin account
Win10 says NO to too many things to run as Admin normally so is using a user account.
Have disconnected all drives except SSD, so it now identifies that as 'C' but still won't boot
REPAIR from CD says NO
Restore wants windows running an operating system to select
rtsrui.exe fails
bootrec rebuild - system device not found
bootrec fixmbr - succeeds
getting box saying werfault.exe failing to reference memory - keeps closing itself & re-appearing

[eLaReF]

Forgot
Just used default repair

[Boggin]

You can turn off Widows Error Reporting in the registry by reading through this article, but you can't create a restore point when in the Recovery Environment.

http://www.thewindowsclub.com/activate-windows-error-reporting-windows-8

Also, at the Command Prompt enter bcdedit |find "osdevice"

If it gives you a partition letter, use that instead of the X I've used in this cmd -

sfc /scannow /offbootdir=X:\ /offwindir=X:\Windows

See if that will run and what it reports.

For clarity, that is a Pipe symbol before find which is the uppercase of \ and there's a space before each /

What sort of things is the default admin account not allowing you to do ?

My Win 10 and Win 7 work fine with just the single admin user account, although you may have to take ownership of system files if you want to do anything with them, but just using a computer as most people do - you shouldn't need to go tampering in those.

[eLaReF]

Thanks
Currently Installing Win10 to a 2nd SSD, which in view of the niggling problems is probably the best thing to do anyway
Can't remember now re the Admin account, It was over a year ago and it happened every time I logged in as Admin, so gave up.
But as the user I was having to run software often as administrator to get access to the Temp folder and others
Basically reckon my Win7 was screwed and the upgrade didn't help.
Thks anyway
Sorry for spoiling yr w/end!
Lets call this closed

[Boggin]

It's not a problem and as long as you've gotten it sorted

I'll add Solved to your thread title but it won't close the thread if you want to add to it.

However, it will be auto locked after 30 days when nothing more has been added to it.