How to Upgrade to Windows Server 2025 Using Windows Update Without Data Loss

Before starting the upgrade, confirm your current Windows Server version and install the mandatory March 2026 cumulative update that enables the Windows Server 2025 feature update path.

# Check current Windows version
Get-ComputerInfo | Select-Object WindowsProductName, WindowsVersion, WindowsBuildLabEx

# Check for required cumulative update
# For Windows Server 2022:
Get-HotFix | Where-Object {$_.HotfixID -eq "KB5078766"}

# For Windows Server 2019:
Get-HotFix | Where-Object {$_.HotfixID -eq "KB5078752"}

If the required update isn't installed, download and install it from Windows Update or Microsoft Update Catalog. This update is essential as it enables the Windows Server 2025 upgrade path through Windows Update.

# Force Windows Update check
Install-Module PSWindowsUpdate -Force
Get-WUInstall -AcceptAll -AutoReboot

Configure the Windows Update client to recognize and offer the Windows Server 2025 feature update. This requires specific registry modifications that tell Windows Update to target the 2025 release.

# Run PowerShell as Administrator
# Enable Windows Server 2025 feature update targeting
New-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\WindowsUpdate\Orchestrator\UScheduler" -Name "BranchReadinessLevel" -Value 2 -PropertyType DWord -Force

New-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\WindowsUpdate\Orchestrator\UScheduler" -Name "TargetReleaseVersion" -Value "25H2" -PropertyType String -Force

# Restart Windows Update service to apply changes
Restart-Service wuauserv -Force

These registry entries configure Windows Update to offer the Windows Server 2025 feature update. The BranchReadinessLevel value of 2 enables feature updates, while TargetReleaseVersion specifies Windows Server 2025 (25H2).

Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\WindowsUpdate\Orchestrator\UScheduler" | Select-Object BranchReadinessLevel, TargetReleaseVersion

Windows Server 2025 requires TPM 2.0 and Virtualization-Based Security (VBS) support. Verify your hardware meets these requirements before attempting the upgrade.

# Check TPM status
Get-Tpm | Select-Object TpmPresent, TpmReady, TpmEnabled

# Verify TPM version
(Get-WmiObject -Namespace "Root\CIMv2\Security\MicrosoftTpm" -Class Win32_Tpm).SpecVersion

# Check VBS capability
Get-CimInstance -ClassName Win32_DeviceGuard -Namespace root\Microsoft\Windows\DeviceGuard | Select-Object VirtualizationBasedSecurityStatus

If TPM 2.0 is not enabled, access your server's BIOS/UEFI settings and enable TPM. For virtual machines, ensure the hypervisor supports virtual TPM 2.0.

# Check if Hyper-V is compatible (for VBS)
Get-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-All | Select-Object State

# Verify secure boot status
Confirm-SecureBootUEFI

Perform a comprehensive backup of your server before starting the upgrade. This includes system state, all data, and server roles configuration.

# Install Windows Server Backup feature if not present
Install-WindowsFeature Windows-Server-Backup -IncludeManagementTools

# Create system state backup
$BackupLocation = "E:\ServerBackup\" # Adjust path as needed
wbadmin start systemstatebackup -backupTarget:$BackupLocation -quiet

# Create full server backup (including all volumes)
wbadmin start backup -backupTarget:$BackupLocation -include:C:,D: -allCritical -quiet

Document your current server configuration, including installed roles, features, and critical settings:

# Export current server roles and features
Get-WindowsFeature | Where-Object InstallState -eq "Installed" | Export-Csv "C:\Temp\InstalledFeatures.csv" -NoTypeInformation

# Export registry settings for critical applications
reg export "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion" "C:\Temp\WindowsVersion.reg"

# Document network configuration
Get-NetIPConfiguration | Export-Csv "C:\Temp\NetworkConfig.csv" -NoTypeInformation

Navigate to Windows Update settings to check for the Windows Server 2025 feature update. This may take several minutes to appear after enabling the registry settings.

Open Settings → Update & Security → Windows Update, then click "Check for updates". The Windows Server 2025 feature update should appear as an optional update.

# Alternative: Check via PowerShell
Get-WUList | Where-Object {$_.Title -like "*Windows Server 2025*"}

# Force update detection
Invoke-WUJob -ComputerName localhost -Script {ipmo PSWindowsUpdate; Get-WUInstall -AcceptAll} -Confirm:$false

If the feature update doesn't appear immediately, wait 10-15 minutes and check again. Windows Update may need time to process the registry changes and contact Microsoft's servers.

Begin the feature update installation process. This will download Windows Server 2025 and perform an in-place upgrade while preserving your data and settings.

In Windows Update, click "Download and install" for the Windows Server 2025 feature update. Review and accept the "Important Information" dialog that explains the upgrade process.

# Monitor download progress via PowerShell
Get-WUHistory | Where-Object {$_.Title -like "*Windows Server 2025*"} | Select-Object Title, Date, Result

# Check available disk space (upgrade requires 20+ GB free)
Get-WmiObject -Class Win32_LogicalDisk | Select-Object DeviceID, @{Name="FreeSpace(GB)";Expression={[math]::Round($_.FreeSpace/1GB,2)}}

The download process typically takes 30-60 minutes depending on your internet connection. Once downloaded, the installation will begin automatically. The system will restart multiple times during this process.

During installation, you'll see progress screens showing "Working on updates" and percentage completion. The server will restart several times - this is normal behavior.

After the upgrade completes, verify the new Windows Server 2025 installation and activate it with a valid product key.

# Verify Windows Server 2025 installation
Get-ComputerInfo | Select-Object WindowsProductName, WindowsVersion, WindowsBuildLabEx

# Check system uptime to confirm successful restart
Get-CimInstance -ClassName Win32_OperatingSystem | Select-Object LastBootUpTime

# Verify all services are running
Get-Service | Where-Object Status -eq "Stopped" | Where-Object StartType -eq "Automatic"

Activate Windows Server 2025 with your new product key. Note that Windows Server 2019/2022 keys are not valid for Windows Server 2025.

# Install Windows Server 2025 product key
slmgr /ipk YOUR-WINDOWS-SERVER-2025-PRODUCT-KEY

# Activate Windows
slmgr /ato

# Verify activation status
slmgr /xpr

Confirm that all previously installed server roles and features are functioning correctly after the upgrade. Some roles may require reconfiguration or updates.

# Compare current features with pre-upgrade backup
$CurrentFeatures = Get-WindowsFeature | Where-Object InstallState -eq "Installed"
$BackupFeatures = Import-Csv "C:\Temp\InstalledFeatures.csv"

# Check for any missing features
$MissingFeatures = Compare-Object $BackupFeatures.Name $CurrentFeatures.Name | Where-Object SideIndicator -eq "<="
$MissingFeatures

# Verify critical services are running
Get-Service | Where-Object {$_.Name -in @("DNS", "DHCP", "W3SVC", "MSSQLSERVER")} | Select-Object Name, Status

Test key server functionality to ensure the upgrade didn't break critical services:

# Test DNS resolution (if DNS server role installed)
Resolve-DnsName google.com

# Test web server (if IIS installed)
Invoke-WebRequest -Uri "http://localhost" -UseBasicParsing

# Check event logs for errors
Get-WinEvent -LogName System -MaxEvents 50 | Where-Object LevelDisplayName -eq "Error"

Install updated drivers and application versions compatible with Windows Server 2025. This ensures optimal performance and security.

# Check for driver updates
Get-WmiObject Win32_PnPSignedDriver | Where-Object {$_.DeviceName -ne $null} | Select-Object DeviceName, DriverVersion, DriverDate | Sort-Object DriverDate

# Update Windows components
Install-Module PSWindowsUpdate -Force
Get-WUInstall -AcceptAll -AutoReboot

# Check Windows Update history
Get-WUHistory | Select-Object Title, Date, Result | Sort-Object Date -Descending

Update critical server applications and verify compatibility:

# Check .NET Framework version
Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\NET Framework Setup\NDP' -Recurse | Get-ItemProperty -Name version -EA 0 | Where-Object {$_.PSChildName -Match '^(?!S)\p{L}'} | Select-Object PSChildName, version

# Verify PowerShell version
$PSVersionTable.PSVersion

# Check Windows Management Framework
Get-ItemProperty "HKLM:SOFTWARE\Microsoft\PowerShell\3\PowerShellEngine" -Name PowerShellVersion