Yes, reformat now.
You've cleared the corrupted Exchange AD debris successfully - that was the vital first step. Now it's time to purge the local filesystem and registry fragments left by the botched install.

Why You Must Reformat

Even though you've cleaned AD, the server itself still contains:

• Incomplete registry keys under HKLM\Software\Microsoft\ExchangeServer\v15


• Broken Exchange services


• Residual mailbox DB folders, logging, config XMLs


• Possibly misregistered .NET assemblies and Windows component state pollution

Trying to reinstall on top of that is like building a church on a sinkhole.

Before You Reformat

Quick checklist:

• 
  DNS is clear? nslookup ARGEX-TEMP shows correct or blank?

  
  



• 
  Static IP or DHCP saved for reuse?

  
  



• 
  Any custom firewall/roles/scripts to back up?

  
  



• 
  Confirm AD is clean:

  
  

  Get-ADObject -LDAPFilter "(name=ArgEX-temp)" -SearchBase "CN=Configuration,DC=argofield,DC=local"
  

  
  

  should return nothing

  
  

Reformat Flow

1. Wipe the OS drive (or re-image the VM)

   
   



2. Install fresh Windows Server 2012 R2 / 2016

   
   



3. Install Windows Updates fully

   
   



4. Join it to the domain again (if needed):

   
   

   netdom join ARGEX-TEMP /domain:argofield.local /userd:admin /passwordd:*
   

   
   



5. Install prerequisites:

   
   
   
   
   • .NET 4.6.2
   
   
   • UCMA 4.0
   
   
   • Desktop Experience, IIS features, etc.
   
   
   
   



6. Install Exchange 2013 CU23:

   
   

   setup.exe /mode:Install /Roles:Mailbox,ClientAccess /IAcceptExchangeServerLicenseTerms_DiagnosticDataOFF /LogLevel:Verbose
   

   
   

Optional: Want a Prereq Script?

I can generate a PowerShell script to install all required Windows roles/features for CU23 on 2012 R2 or 2016 - just say the word.

You've exorcised the ghost. Reformat, rebuild - and this time it'll sing. Let me know when you're ready to run the Exchange installer fresh, and I'll double-check it's staged cleanly.

Excellent work, you're now back on solid ground, clean OS, clean AD, and no cursed registry bits hiding under the floorboards.

Let's now make sure the Exchange 2013 CU23 install completes flawlessly.

Final Preflight Checklist Before Running Setup

Run through this quick set of checks - we want to avoid hitting mid-install walls again:

1. Hostname Check

Is the hostname still ARGEX-TEMP?

• Confirm:

  
  

  hostname
  

  
  



• Make sure this matches exactly what was used before in AD - no trailing dashes, no typos.

  
  

2. Domain Join Check

• Confirm you are joined to the domain:

  
  

  systeminfo | findstr /i "domain"
  

  
  

  Should return:

  
  

  Domain: argofield.local
  

  
  

3. Install All Exchange 2013 Prerequisites

For Windows Server 2012 R2 (most common for Exchange 2013), run this in elevated PowerShell:

Install-WindowsFeature AS-HTTP-Activation, Desktop-Experience, NET-Framework-45-Features, RPC-over-HTTP-proxy, RSAT-Clustering, RSAT-Clustering-CmdInterface, RSAT-Clustering-Mgmt, RSAT-Clustering-PowerShell, Web-Mgmt-Console, WAS-Process-Model, Web-Asp-Net45, Web-Basic-Auth, Web-Client-Auth, Web-Digest-Auth, Web-Dir-Browsing, Web-Dyn-Compression, Web-Http-Errors, Web-Http-Logging, Web-Http-Redirect, Web-Http-Tracing, Web-ISAPI-Ext, Web-ISAPI-Filter, Web-Lgcy-Mgmt-Console, Web-Metabase, Web-Net-Ext45, Web-Request-Monitor, Web-Server, Web-Stat-Compression, Web-Static-Content, Web-Default-Doc, Web-Windows-Auth, Web-WMI, Windows-Identity-Foundation

Then reboot.

And Install:

• UCMA 4.0 Runtime:
  Download Link (Microsoft)

  
  



• .NET Framework 4.6.2 (if not present)
  Check with:

  
  

  (Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full').Release
  

  
  

  If under 394802, update it.

  
  

4. Extract the CU23 Media to a Local Folder

Do not run setup from a ZIP or mapped drive.

U:\Exchange2013CU23\setup.exe

Run Exchange 2013 Setup

Once you've confirmed all above:

setup.exe /mode:Install /Roles:Mailbox,ClientAccess /IAcceptExchangeServerLicenseTerms_DiagnosticDataOFF /LogLevel:Verbose

That's all you need.

Post-Install Checklist (When It's Done)

After successful install, check:

Get-ExchangeServer
Get-MailboxDatabase
Test-ServiceHealth

Then open EAC at:

https://ARGEX-TEMP/ecp

Let me know when setup starts or if you hit any prompt or failure mid-way - I'll stay with you through it if anything grumbles.
You're about to finish this the clean way.