Server migration from Windows Server 2008 and 2012 to 2019 and 2025

Associate Consultant, Tata Consultancy Services (November 2022 to present)

Moved over 800 servers from Windows Server 2008 and 2012 to 2019 and 2025 inside change windows, with no unplanned downtime.

The problem

Hundreds of servers were running Windows Server versions that no longer received security updates, and each had to move without interrupting the service it supported.

What I did

Each migration ran inside an approved change window with a tested plan. Every new server received CIS benchmark hardening, and any vulnerability found was remediated before the server went live.

The result

Over 800 servers were migrated to Windows Server 2019 and 2025 with no unplanned downtime. Every server is hardened to the CIS benchmark.

DNS dependency analysis tool

A PowerShell tool that found unknown DNS dependencies across over 800 servers, so legacy DNS servers could be retired without disruption.

  • PowerShell
  • Windows Server DNS
  • Active Directory
  • Git