Unable to install Windows due to 2 serperate volumes being marked as C

The commands are diskpart commands that can display the current drives, partitions and volumes.

The op is asking a reasonable question. Telling him to delete partitions on which he repeatedly stated he has data is not an answer.

I would try this from winpe

format the old windows partition
create an esp partition
apply the image from boot media using dism onto the old windows partition

bcdboot windowspartitionletter:\windows /s espletter:

now reboot out of winpe and into the hard disk.

However, it is possible the installation media is corrupted

SIW2 said:

The op is asking a reasonable question. Telling him to delete partitions on which he repeatedly stated he has data is not an answer.

Agree.

What I would do is boot from the Installation USB flash drive. At the first screen press shift+F10 to get into command prompt. Use diskpart to examine the discs, especially the one being installed to. Delete every partition that are not the desired data partitions. Look at the existing volume letters, select each remaining volume and remove it's letter with the "remove" command in diskpart. So there should be nothing left but data partitions with no drive letters assigned and unallocated space.

Then select the custom install option, highlight the unallocated space to install to and click next. At that point if the error comes back, then there must be something wrong with the existing disc partitioning or the USB flash drive. Also, since this was due to a malware infection. it's possible the virus infected the area of the disc where partitions are defined and that might be causing a problem.

Post #5

Have you tried using using diskpart to change one of those letters?

OP reply in post #10

Well yes I have tried changing the C Drive multiple times from Diskpart, but the damn installer sets it back since its so "smart".

Which is why I suggest he doesn't use setup.exe on the boot media and instead applies the image using dism.

Delete every partition that are not the desired data partitions.

In this post #17 he says he tried that. Unable to install Windows due to 2 serperate volumes being marked as C

He can't boot, so he would need to run it in the repair environment.

You might look into the portable Emsisoft's Emergency Kit.

Emsisoft | Emergency Kit: Free Portable Malware Scan and Removal

EEK is not bootable, but it can be run by booting from the Windows install media, selecting Repair > Troubleshoot > Command Prompt.

Use DISKPART > list volume to find the drive letter you want to scan, and the drive letter of the flash drive where EEK was saved.

The EEK readme file has an example -

- Switch to the Emsisoft Emergency Kit folder (e.g.: cd Drive Letter:\eek\bin64\).

- Run the scanner by typing: a2cmd.exe

Next you will see a help page describing all available parameters. (attached above)

The following parameter is an example of scanning drive c:\ with Memory and Traces (Registry) scan enabled, and archive support active.

Detected Malware is moved to the default quarantine folder.

a2cmd.exe /f="c:" /m /t /a /q="Drive Letter:\eek\quarantine"

sreyan32 said:

And I have discovered the root of the problem. The installer is so buggy and useless it is actually marking the Recovery partition as C:.

You have indeed find out the problem, but just one step is missing.
In any case even if you succeed other issues might arise later.

From the screenshot HERE it looks like you want to install Windows to partition E (volume 0, which is 199GB)? (please double verify this)

Once you boot into installer, press SHIFT + F10 to open command prompt.
Select each partition that has no drive letter assigned like this:
select partition PART_NUM
Replace PART_NUM with real partition number
then type:
assign

Once all partition have drive letters assigned, continue installing windows to partition (to which you intend to install OS) even if it's not marked as C:\, it could be H:\ just make sure that's the partition you want to install to and that it contains no data.

Once OS is installed and once installer reboots into new OS it will be renamed to C:\ automatically.
Even if it's not renamed to C:\ it doesn't matter, you can do it in Windows explorer later.

From later screenshots it's no longer clear which partition is which one, so I choose just one screenshot as an example.
Booting installer from disk is a bit different than from USB.